Transcript for:
Overview of Red Hat RHCSA Certification

hi there it's paul from howtonetwork.com i've just uploaded the entire red heart red hat rhcsa certification so the red hat and associate it's a uh for an out of date version of red hat so there's a new version so i thought i'd upload the course here it should all work but just don't research the difference between the version used on this course and then the latest version this was the original course page for the exam so as i said um the exam stayed the same i think the code's even the same but they just um maybe have new features and functions in the new version so it's around eight hours long on the website there's some um an undercourse certificate which i can't give you obviously because you're on youtube but there's some follow-along labs as i said there may be a few little differences but um i'll leave it to you to research so i hope you enjoy it and i'm going to be releasing some other full courses on youtube so if you don't mind if you could subscribe and hit the bell and give the video a thumbs up it really helps the algorithm because then we get some more advertisements and it helps pay for some more courses the only other thing is in the course when it was first written we were installing all these operating systems on our home pc so what i recommend you do is use virtualbox or a vmware whatever you prefer and you can um install your operating system you can see i've got windows here a firewall ubuntu windows but i've also got red hat so there's loads of videos on youtube showing you how to use virtualbox it's free you can download red hat for free also and do all of the labs and follow along with the instructor so that's all i've got to say i hope you enjoy the course and as i said um i'd really appreciate it if you give us a subscribe or at least one of the thumbs up and drop a comment i'll see you on the next course [Music] in this lesson i will introduce you to the red hat linux operating system what is an operating system an operating system is an interface between user and hardware so how does it work let us see the user will enter input through the operating system the os and the os will process that request and it will give it to the hardware the hardware will process the request and give it back to the os from the os the user will get the output of the given input in this way an operating system will act between hardware and user so an operating system is an interface between user and hardware in the world there are many types of operating systems like linux windows mac os and chrome os then why why are we here to learn linux because of its advantages what are the advantages of red hat linux compared to other operating systems one is security so compared to other operating systems red hat linux is more secure than other operating systems flexibility compared to other operating systems it is very flexible compatibility red hat linux is very compatible on almost any hardware so we can easily install and use the operating system cost compared to other operating systems it costs less some linux versions will come free of cost so we can use the operating system for free so compared to other operating systems red hat has more freedom we can use whatever hardware we have so red hat linux will install on any hardware so we have plenty of freedom compared to other operating systems so these are all the advantages of red hat linux security flexibility compatibility cost and freedom so what is a kernel the kernel is the core of the os it is the interface between the hardware and the shell so what is meant by shell shell is a command line interpreter it is an interface between the kernel and program or user so how does the kernel and shell interact in the red hat linux architecture linux architecture consists of programs or user shell kernel and hardware initially the programmer will interact with the shell through commands the shell will interact with the kernel the kernel will interact with the hardware in the hardware it will process the request and it will give the output to the kernel from the kernel the output will be given to the shell and from the shell the user will get the output and he will make use of that output linux architecture has been divided in this way next we will discuss the history of red hat linux linux was first developed by linux torvald in the year 1991 his linux kernel was given to the open source foundation the first version of linux was 0.01 what is the open source foundation the open source foundation was a non-profit organization and it was founded in the year 1998 under the us national cooperative research act of 1984 to create an open standard for an implementation of the unix operating system in february 1996 the open source foundation merged with x open to become the open group this open source foundation consists of free operating systems and software under the gpl gpl stands for general public license the general public license is the most widely used free software license which guarantees end users like individuals organizations and companies the freedom to use study share and modify the software the linux kernel was bundled with many different software packages from various distributions for this reason it gave rise to many flavors of linux there is mandrake slackware ubuntu red hat and so on of these flavors red hat is very popular compared to other flavors red hat was commercialized in the year 1995. red hat has two types of versions one is a free version that is fedora and scent os the second one is a commercial version that is red hat enterprise edition so what is the difference between fedora centos and red hat linux fedora run by the red hat company focuses on quick releases and it is a free operating system red hat is based on fedora and run by the red hat company every two years a version will be released and it is a commercialized version scent os basically it is a red hat version without the cost or support for cent os red hat won't give any support these are all the differences between fedora red hat and centos in this lesson i have introduced red hat linux what is the kernel the shell the history of linux and what are the different flavors of linux in the next lesson we will discuss basic installation thank you so [Music] in this lesson we will discuss how to install red hat linux there are many ways to install linux but in this lesson i will use a dvd to install the operating system first insert the dvd in the dvd drive of the computer and boot the system after booting the system we can see the installation welcome screen of red hat linux on that screen there are many options like install or upgrade install system with video drivers please select install or upgrade in order to proceed with the installation after that we can see the disk found screen on that screen it will ask us to check the media here we can press the skip button to proceed further click the next button to proceed with the installation select the language as per your preferences here i am using english as the language click next to proceed further click next again to proceed further in this step we can see two options one is basic storage device and the second one is specialized storage device please use basic storage device and click next it will prompt you to format the hard disk click yes discard any data to format the hard disk in this step please enter the host name i am using chre01 as the hostname and click next to proceed further select the time zone to continue here i am using american time then click next please enter the root password and confirm it click next it says we have chosen a weak password we can click use anyway here we can see many options please use replace existing linux systems and click next click on write changes to disk to proceed further it will create the different file systems in order to install the operating system here we can see many options i am using desktop as my option to install the operating system press next to proceed further after that it will proceed with installation depending on the system hardware it will take some time to install the operating system please monitor the installation if the machine has a lot of memory and a fast processor the installation will complete in a couple of minutes for this desktop installation the total number of packages it needs to install is 1108. we can see on the left side at the bottom the installation packages after installing the packages we need to reboot the machine manually click on reboot to proceed further we can change a few settings in this module just click forward to proceed further you need to accept the license agreement click forward to proceed further and click forward again here you need to enter a username apart from root i am using user as the username then enter a password and confirm it please click forward to proceed further click forward and click finish to complete the installation please enter the password to log into the machine and this is how we install red hat linux on a machine in the next lesson we will discuss red hat linux desktop [Music] in this lesson we will discuss the red hat linux desktop we can see two panels one is at the top and one is at the bottom in order to create a new panel just right click and click on new panel we can see here a new panel on the right side of the desktop these panels are very useful to store the shortcuts to delete a new panel just right-click and click on delete this panel in this way we can create and delete the panels on the right bottom side of the screen we can see two buttons these buttons are called workspace buttons a workspace is a group of applications that are running in one environment different applications can run in different workspaces for example if i want to run calculator in one workspace in another workspace i can run a different application this way a user can run different applications in different workspaces to add a new workspace just right-click go to preferences and enter the number of workspaces you require by adding workspaces we can see new buttons in the right bottom of the screen in this way we can add new workspaces to delete a workspace just decrease the numbers in this way we can create and delete new workspaces to add a shortcut to the panel just go to the application and drag the application to the panel in this way we can create shortcuts to the panel create a shortcut to the panel just right-click click on add to panel and select the application you want to add to the panel and click add we can see a new button in the panel in this way we can add new applications to the panel to delete a shortcut from the panel just right-click and click on remove from panel to delete a shortcut from the panel just click remove from panel in this way we can add and delete the shortcuts to change date and time right click on the upper right button and go to preferences click on general click on time settings so from here we can change the time to change the date and time root password is required after entering the root password the date and time will change if you want to add a new location just go to locations and click on add and select your time zone from the drop down list enter the location name and click ok in this way we can add a new location to delete a new location just click on location and click remove to change the weather settings click on weather and select options from the drop-down list in this way we can change date and time location and weather to change the desktop background just right click and click on change desktop background and click on and click on the image you want to use as the background so we can see a new background now and click close in this way we can change a new background for the red hat linux desktop in the left top we can see the applications button from here we can explore many applications such as accessories graphics internet sound and video and system tools you can explore these applications for yourself places is a shortcut for a particular folder click music it will take you directly to the music folder click on documents it will go directly to documents in this way we can go directly to a particular folder system the system button consists of preferences administration and documentation preferences allow us to change settings and tweak for better performance of red hat linux so we can change settings from here administration consists of security settings we can change for better performance documentation from documentation we can get more details about red hat linux here you can read more about red hat linux we can get more help from the help button here we can get more help for a particular topic from the search box we can search for a particular topic i'm searching for sound it will provide some help pages from here we can get more help for sound to check which version of red hat linux is running on your system just click on system and go to about about this computer will provide more information about your system from here we can get more information like what version of linux is running and hardware details such as how many processors are running this is like the task manager in windows you can also see resources and file systems you can lock the screen by pressing lock screen so the system has been locked now after entering the password you can enter back into red hat linux if you want to log out the user just click on log out user it will ask you permission so if you want to log out just click on log out now we have logged out from the system in order to log into the system just click on the user and enter the password in this way we can log in and log out from the system [Music] in this lesson we will discuss linux commands to view the calendar cal is the command type cal and press enter you can see the present month of the calendar in the same way if you want to see a particular calendar year the command is cal and the year in this way we can see the whole calendar year if you want to see a particular month and particular year of the calendar the command is cal month after that we need to type the year so in this way we can see a particular month of a particular year if you want to clear the screen the command is clear just press enter so it will clear the entire screen clear is the command which we will use repeatedly to clear the screen the next command is date this command will give you today's date and time this command is very useful if you are working on any server to know the date and time of a particular server to know current user information who am i is the command type who am i and press enter it will show you information about the user that's logged in to know which commands you ran previously the command is history it will show you all the commands you ran previously type history and press enter so these are all the commands which we have run previously in this way we can see previously ran commands to know which version of the operating system you are using the command is you name and press enter it will give you the output of which version we are using if you want more details we need to use options you name dash a it will give you entire details of the linux version you are using working on commands is very interesting sometimes you don't know which command is useful for which operation when that happens there are many useful commands which we can use to get more details about a particular command the command is man and you need to give the command name for example previously we have used many commands let's say i don't know too much about the history command and i want to know more details about it for that one we need to type man space history in this way we can get more details about a particular command so as you can see we can get details about any command and we can see the options for that command these are all the options we can use for the history command in order to quit from this man page just press q so we can come out from that command this man command is very useful if you don't know the operation of a particular command if you want to know which options you need to use for a particular command we can get it from the man page also there are other methods that show which options can be used for a particular command if you don't know which option you need to use for a particular command just give the command with the option hyphen hyphen help this will show us which options are available for a particular command so these are all the options which we can use you can get a brief description about a command by using info command here we can see that the function of the ls command is to list directory contents info is a very useful command which will give us more details about a particular command in order to leave this page press q so in this way you can get more details about a particular command if you want a short description about a command we can get those details by running the command what is the syntax is what is space command ls is the command we will use in this example in this way we can get a short description about a particular command let's create a dummy file type touch file name in this case file1 this will create a dummy file so in that file there won't be any data touch is a very useful command if you want to create multiple files by using a single command let's do a demonstration if you want to create multiple files just type touch file 1 is already created so let's type file 2 space file 3 space file for you need to put spaces between the files and press enter three files will be created if you want to see the files that we have created just use the ls command it will show you the files we just created by using the touch command these four are the files which we have created to create a new file the command is cat and the syntax is cat greater than file name after that we press enter it will go to the edit prompt where we can edit the file to go to the next line press enter in order to save this file press ctrl d it will save the file to see this file the command is cat and the file name and press enter to create a new directory the command is mkdir and the directory name and press enter in this way we can create a new directory the command to check the current working path is pwd pwd stands for present working path this command is very useful to tell us which path we're working in currently we are working under slash root the command to list the files and directories under a particular path is ls ls will show us all the files and directories under a particular directory there are many options which we can use for ls to get more details about directories and files here i am using hyphen l to get more details about the files and directories under a particular path the command to change the directory is cd first check under which path we are working type the pwd command and press enter currently we are working under root if we want to change a particular directory the command is cd and the directory name in this way we can move from one directory to another directory you can check whether we have moved to a particular directory or not by using the pwd command so here we have changed from slash root directory to slash root slash der and this is how we move from one directory to another directory to copy files from one location to another location the command is cp source path and destination path here i am copying file 1 to destination slash root dir in this way we can copy a particular file from one path to another path let's see if the file copied to slash root slash dir i am changing directory to slash root slash dir and give the command ls we can see file1 so this is how you copy a file from one particular location to another location there are many options for the cp command if you want to copy all the files under a particular path the command is cp dash r in this way we can copy all the files from one location to a different location the command to move a file from one location to another location is mv source path and the destination path let's see what files we have in this directory so let's demonstrate this with file 2. we will try to move file 2 from one path to another path type the command mv space me [Music] in this lesson we will talk about a few more linux commands the ls command is used to check the files and directories under a particular path here we can see file1 and file2 are the files under the dir directory so i want to remove file 2 from this location the command is rm and the file name the syntax is rm space file name press enter and press yes so it will remove the file from this location let's see if file 2 exists in this path or not run the ls command so file 2 has been removed from this path now i'll change directory to slash root to remove a directory let's clear the screen now use the ls command to check what the directories are under this path we have created the dir directory previously now i want to see if i can delete that directory rmdir is the command to delete directories and the syntax is rmdir and the directory name press enter rmdir will remove only empty directories in dir there is the file1 file so it was unable to delete by using rmdir so we will remove file1 first rm file1 press y to proceed further run ls command to check if any files are there under the directory currently there's no more files under dir let's change the directory to slash root run ls command to check files and directories under this path and now i will try to remove the dir directory rmdir space dir again rmdir is the command to remove the directory so the syntax is rmdir space directory name press enter after pressing enter the directory has been removed now let's check whether the dir directory has been removed or not run the ls command to check the directory so the dir directory has been removed there are many options for rm rm-r rm-r will remove all the directories recursively from that particular path rm-f rm-f is the command to forcefully remove all the files and directories under a particular path there are many options for rm but these two options will be most useful to create links in linux the command is ln source path and destination path let's create one link for a file just type ls so i want to create a link for install.log so the command is ln the source path and the destination path and the destination path is slash root dir in this way we can create a link for a particular file let's check whether the link exists in the destination path run the ls command so install.log has been linked from slash root to slash root slash dir in this way we can create links for particular files and directories if you want to unlink this file just run the command unlink and the file name this is how you unlink created links run the ls command to check whether the link still exists or not the link has been removed now type head how many lines you want to see and then the file name we are able to see the first 15 lines from this file the head command is very useful if you want to see a few lines from the top tail shows you lines from the bottom and the syntax is tail space how many lines you want to see from the bottom and the file name in this way we can see the top 15 lines and the bottom 15 lines if you want to count how many lines how many words how many characters in a particular file wc is the command so if you want to see how many lines the option is dash l and the file name there are a total of 64 lines that exist in that file if you want to check how many words in a particular file wc-w is the option and the file name so a total of 149 words are present in that file if you want to see how many characters are present in a particular file the command is wc dash c and the file name there's a total of 1560 characters that are present in that file this command is very useful if you want to count lines words and characters in this lesson we have discussed a few linux commands in the next lesson we will discuss advanced linux commands thank you so [Music] in this lesson we will discuss advanced linux commands first we will start with the grep command the grep command is used to search a pattern in a file or directories we will use many wild characters for the grep command let's see how to use the grep command to search for patterns for example if you need to check a directory or a file under the present working directory we run the command ls dash l pipe grep dir star so this command will check all the dir-related information under the root directory press enter currently there is no dir related information in this path if you want to search a file or directory under the present working directory the command is ls dash lai pipe grep and the directory name for which you are searching so it will give you the output that was related to the search pattern in this way we can search files or directories under a particular path we can search patterns in files also for that we need to create or use an existing file under this path i am searching the anaconda ks cfg file to search so let's check what information exists in the anaconda ks file there is much information that exists in the anaconda file so i need to search with some pattern by using the grep command for example i'll search for a cp pattern in the file anaconda so it will give you the output that is related to the cp search pattern here we can see many cps that were related to the search pattern in this way we can search particular patterns in the files so the grep command is very useful to search for patterns under a directory or in files there are many options which we can use for grep type grep dash dash help and we see the options you can try two or three options to check what output you are getting for example if you want to search for a pattern here we can search the option grep i the dash i option is used to ignore case sensitivity for example we have dir the dir directory is under this path so we will search for dir directories using the grep command with capital letters here we search the pattern dir with capital letters so that dir does not exist in this path so if you put option i it will ignore the case sensitivity and it will give you the output of the files that are related to dir in this way the pattern will ignore by using the hyphen option let's see how this command will work without the dash i me [Music] in this lesson we will discuss how to change permissions owners and groups for files and directories chmod will be used to change permissions on files and directories here are the values for r the value will be 4. for suid the value will be 4. for w the value will be 2. for sgid the value will be 2. for x the value will be 1 and for sticky bit the value will be 1. so what is meant by rwx r stands for readable w stands for writable x means executable these are all the permissions which will be used on files and directories suid sgid and stickybit are the special permissions which we will implement on files and directories so how will we calculate these values to apply permissions on files and directories the calculation will be if we need to apply r w x the value will be four plus two plus one we need to add the r value the w value and the x value so in this way the calculation will be applied to the files and directories in order to apply permissions if we are giving rx the value will be four plus one which equals five so for files and directories the permissions will be classified as below owners groups and others so here for owner rwx the value will be 7 and group 7 and others 7. for rx for owner the value will be five the group value will be five for others the value will be five for rw the value will be six for group value six for others the value will be six for files and directories the suid sgid and sticky bit permissions will be classified as below for owners groups and others suid has been classified as rws we will see the s symbol if a file or directory has suid permissions for sgid we will see for group rws if the file and directory consists of sgid we will see rwt for sticky bit for others if the file consists of sticky bit permission the advantage of sticky bit is only the owner is able to delete to change the permissions for a file or directory we have a command chmod first check what the permissions are that are existing for a file by running the command ls dash lai we will change permissions for new directory the command to change permissions for a file or directory is chmod so i want to add write permission for both group and others for that we need to run the command chmod g plus w comma o plus w this will enable write permission for group and write permission for others and we need to specify the file or directory name here i am specifying new dir in this way we can change permissions for a file or a directory so now let's check whether the permissions have been updated to the new directory or not by running the command ls dash lai so from here we came to know that write permission has been successfully added to new directory by using the command chmod if you want to delete any permissions from file or directory the same command chmod will be useful we will change permissions for new dir so i want to delete read and write permission for others that is 0 minus rw for group [Music] in this lesson we will discuss the linux file structure so root is the parent directory in linux let's examine the importances of different directories in the linux file structure bin and user slash bin consist of user commands so all the normal user commands are stored in bin and user slash bin sbin and user sbin consist of all admin commands these commands are nothing but root commands etc consists of all system and network configuration files slash usr consists of all man pages and documents slash lib consists of all modules in the slash lib directory all the programmable modules will be saved after that slash var consists of all system log files slash opt consists of all third party plugins if you want to install any third party package we need to install it under slash opt slash tmp consists of temporary files slash devices consist of all physical device information this device information is for kernel reference only slash dev consists of all logical device information this is for human reference and at last the user's home directory under slash home all the users home directories will exist in this way linux file structure has been divided into different directories so every directory has its own importance like windows it will be divided into partitions like c d e and f next we will proceed with the boot process so how does the linux boot process work first the bios will check for bootable devices on the machine after checking bootable devices it will check for a master boot record on that device after that it will check for a partition table on that device and after that it will check for a bootloader a bootloader consists of all bootable files in linux the bootloader will be grub so it will check for the grub boot loader after that it will check for a kernel the kernel consists of all core operating system files and after that it will mount slash root and usr in a read-only mode and then it will check for etc init tab etc init tab consists of the default run level after that it will check for etc f-stab which consists of all mount details so by getting these details it will remount all file systems and this is the way the boot process works in linux what are run levels in linux there are many run levels in linux the first one is run level 0 which consists of power off so in run level 0 the system will power off the second one is run level 1 which is a single user mode with only text mode run level 2 multi-user mode with text mode supports all services except nfs and nis run level 3 multi-user text mode supports all services in red hat linux the default run level is 3. run level 4 is unused so it is used for future purposes and the run level multi-user with graphical mode supports all services these are all the different run levels that exist in linux these are all the red hat linux run levels so the default run level is run level 3. so in this lesson we learned about the linux file structure boot process and what the different run levels are in linux thank you [Music] in this lesson we will talk about the vi and vim editor the vi editor is nothing but a command line tool for a text editor we already know the cat command will create new files by running the command cat greater than file name after that we need to enter the data here and then press enter ctrl d it is very difficult to create files using the cat command to overcome this problem vi editor has been introduced the vi editor is a command line tool to edit files to edit files we need to run the command vi file name and press enter vi editor has three modes one is insert mode we need to press i on the keyboard we can see the vi editor in insert mode in the left bottom side of the editor after that we can edit the file so in insert mode we are able to edit the file and we have another mode in vi editor that is escape mode from here we are able to search replace delete and copy in this mode we can see that the insert option has been changed in the left bottom side of the vi editor from here we are able to search replace delete or copy to search a pattern in the file just enter forward slash we can see forward slash in the bottom left hand side of the editor after that we need to give the pattern to search and press enter here i'm searching for a pattern home press enter and it will take you to the home keyword in this way we can search any pattern in the vi editor the third mode is colon mode this mode is very useful to save and quit the file or just quit the file to use it press colon on the keyboard we can see the colon on the bottom left side of the editor to save the file we need to type wq wq is the option to save the file on the vi editor if you want to save the file forcefully we need to type the exclamation mark after that press enter so in this way we can save a file which was edited by the vi editor to check whether the file has been successfully saved or not just run the command cat file for and we can see the modified file here if you don't want to modify this file just go to the colon mode and after that simply type q q means quit w means write so if you are using wq it will write and quit if you are using simply q it will quit from the vi editor if you use an exclamation mark here it will forcefully quit from the vi editor for example in this file i will remove the third and fourth line just by pressing the delete button on the keyboard in insert mode after that i want to quit this file without saving for that go to colon mode first go to escape mode and after that press colon on the keyboard so that it will go into colon mode if you are in insert mode first you need to press escape after that if you want to go into colon mode you need to press the colon on the keyboard so here i don't want to save any changes in this file so i will just type q in colon mode and after that press enter it will give an error no write since last change to override this option just go to colon mode and quit forcefully by typing exclamation mark and pressing enter so i have tried to edit this file but i quit without saving the file let's see by running the command cat file 4 and pressing enter we can see the third and fourth line exist in the file because we quit the file without saving in this way we can use the vi editor this vi editor is very useful in editing configuration files such as etc fstab etc init d or some other configuration files so you need to practice well in vi editor after vi editor there is an advanced editor in linux that is vim this is the advanced version of vi editor and we have a few options in vim editor type vim and press enter from here we can see the options that exist in vim editor so if you want to edit a file in vim editor just give the command vim 504 you can get more help for this vim editor by running the command colon help it will give you more information about the vim editor so we can get more details from there again this is the advanced version of the vi editor to leave this screen just press colon and queue it will leave the help file and go to the normal vim editor if you want to quit from here go to colon mode and press q and after that press enter in this way we can get more information about the vim editor the vim editor is nothing but an advanced version of the vi editor so we can use all the options of the vi editor in the vim editor in this way we can edit files by using vi and vim editor in this lesson we learned how to edit files with the vi and vim editor thank you [Music] in this lesson we will discuss user administration user administration is nothing but adding users and groups to the machine for that we can add users and groups in both gui and command line first we will talk about how to add users through gui go to system and click on administration users and groups enter the root password from here we can see what the users and groups are that are currently added to the machine if you want to add a new user just click on add user i'm entering the username as oracle full name as oracle type a password and click on ok it will create a new user with oracle as the username click yes to proceed further in this way we can create a new user in the linux machine to check groups just click on groups from here we can see what the groups are that are currently available to add a new group just click on add group and enter the group name here i'm making the group name sql click ok so it will create a new group with sql as the name in this way we can add users and groups through the gui to add users and groups through the command line just go to terminal and switch to root to add a new user the command is user add i will add the user name java in this way we can add a user through the command line for every user there should be a password to add a password to the java user the command is password java in this way we can add a password to the users so here you need to type the new password in this way we can add passwords to users to see details about users we have two files that consists of all the user information those files are etc password in the bottom of the file we can see java which was added earlier this file is very useful while administrating the users we can get more [Music] in this lesson we will discuss how to create a new file system after adding a hard disk to the machine we need to utilize that hard disk by creating new file systems in this machine i have added a new 20 gigabyte hard disk and i will use that hard disk to create a new file system the command to check if a file system already exists is fdisk and the syntax is fdisk dash l fdisk dash l will provide all the details about connected hard disks and file systems from here we can see the disk slash dev slash sda contains 21.5 gigabytes these are the details about the created file systems the new hard disk that was attached is slash dev slash sdb and contains 21.5 gigabytes so i will use this hard disk to create a new file system [Music] in this lesson we will discuss file system checking and swap management sometimes file systems get errors and users are unable to read and write their data from the file system at that time users will ask us to run a file system check on a particular file system first of all we need to run the command df h it will give you all the file systems that are connected to the machine in this lesson i will use slash dev slash sdb1 for file system checking to proceed with file system checking first of all you need to know that the file system should not be mounted here by running the command df-h you can see that slash dev slash sdb1 has been mounted on new partition first we need to unmount that file system the command for this is u-mount slash and the mount point in this way we can disconnect the file system from the mount point after that run the command df-h so we see that dev slash sdb1 has been successfully unmounted after that you need to know which type of file system it is in linux there are many types of file systems for example ext2 ext3 and ext4 so first you need to know which type of file system it is for this you need to open cat slash etc fs tab by opening this file you will see which type of file system it is we can see that slash dev slash sdb1 has the ext4 file system so to check the file system first we need to unmount the file system and we need to know which type of file system it is after that to check the file system the command is fsck and type ext4 and the file system name here we are running the file system check for sdb1 then press enter it will give you the output and we can see the file system is clean and looks good if you want more options on fsck just run the command fsck so [Music] in this lesson we will discuss how to reset the root password without knowing the original root password this is one of the possible questions which you can face in the red hat certification exam to reset the root password first we need to enter into the single user mode for that we need to reboot the host so we need to enter into the grub prompt this is the grub prompt in which we can edit the kernel for that we need to press e to edit the kernel after that we need to go to kernel and to edit the kernel we need to go to the second line and press e here you need to type space 1. this means we need to boot the host using single user mode after that press enter then press b to boot the machine in single user mode the machine will boot into single user mode now from here we can reset the root password so from here we can see that we are in the root prompt so we have access to reset the root password from here we can reset the root password just type the command pass wd which is similar to resetting the password for normal user after that we need to type the username which is root then press enter from here we can reset the root password just enter the root password press enter after that re-enter the same password again so in this way we can reset the root password through single user mode this is one of the questions which we can face in the red hat certification exam after that enter the reboot command so that it will reboot the host normally so this is the way we can reset the root password without knowing the original root password after that press enter so we learned how to reset the root password now we will check how to set a password for the grub prompt so for that we need to give the command grub dash md5-crypt we need to point out this file to the grub.conf file in this way we can redirect the output to slash boot slash grub slash grub.conf after redirecting the output to grub.conf we can edit the grub password it will go to the password prompt and we can type the password here after that retype the password and press enter so we have successfully created a grub password after editing the grub password we need to check if it is updated using vi slash boot slash grub slash grub dot conf this is the main configuration file for grub here we need to edit the password information we can see the new password that was created previously by running the command grub dash md5-crypt this password needs to be updated in the configuration file after hidden menu just go to hidden menu after that press enter and give the password information by creating a new line password dash dash md5 and the encrypted password which we can copy from here in this way we can create a password for the grub prompt after that save the file and check whether grub is asking for a password or not by rebooting the host so we are here in the grub prompt to enter the password press p it will ask for the password enter the grub password to edit the grub prompt after that press enter now we can edit the grub prompt by pressing e so from here we can edit the grub prompt and this is how we put a password in for the grub prompt so in this lesson we learned how to edit a new password for root and how to create a password for grub thank you [Music] in this lesson we will discuss disk quotas disk quotas restrict the amount of disk space utilized by users and groups it will increase the system performance disk quotas will be implemented only on file systems first check what the existing file systems are on the machine by running the command fdisk l we will use slash dev sdb2 to implement disk quotas first check whether the file system has been mounted or not by running the command df-h the file system has been mounted on slash quota so we need to remount the file system to enable disk quotas on this file system the command is mount dash o remount comma usr quota usr quota is to enable user quota comma grp quota grp quota is to enable group quota after that we need to type the file system name and after that the mount point in this way we can remount the file system to enable user and group quota after enabling group quota on the file system we need to edit etc fs tab to make it permanent so here we need to create a new entry for the file system slash dev slash sdb the file system is slash dev slash sdb2 the mount point will be quota and the type of file system is [Music] in this lesson we will discuss volume and printer management although the linux file system will allow you to automatically mount external drives sometimes it will fail to mount those file systems when that happens we can manually mount that file system for example if you want to mount a floppy drive in the linux file system the command is mount slash dev slash fd0 fd0 stands for floppy disk so if you want to mount this floppy disk the command is mount slash dev fd0 and the mount point here i will use slash mnt as the mount point for external drives so in this way we can mount a floppy disk all the device information will be stored in cd slash dev from here we can see all the device information so these are all the devices that are currently attached to the file system if you want to mount to the linux file system the command is mount slash dev slash cd-rom slash mount point in this system already a mount point exists for cd-rom let's check whether it has been mounted or not by running the command df-h on this linux machine dvd-rom has already been attached we will see how we can mount that dvd to this linux machine through the command prompt the command is mount slash dev slash sr0 and then type the mount point here i'm typing the mount point as media slash after that press enter so we can see the slash dev slash sr0 has been successfully mounted by running the command df-h we can see from the last line that the dvd has been successfully mounted on slash if you want to check go to cd slash media and run the command ls lai from here we can see that the dvd rom has been successfully mounted in the machine in this way we can mount a dvd on the machine by running the command mount slash dev slash sr0 and the mount point if you want to unmount this file system just run the command unmount slash media run the command df-h we can see the dvd-rom has been successfully unmounted from the machine in this way we can mount and unmount the dvd-rom we can see the mounted dvd-rom from the gui by double-clicking computer here we can see that [Music] in this lesson we will discuss how to automate or schedule jobs there are two ways to schedule jobs and we will go over those commands the first one is at the add command is used to schedule jobs for execution at a later time this command will execute only once so if you want to schedule a command once we can use the at command for example if you want to schedule a reboot after 15 minutes the command is first we need to check the time on the machine by running the command date so currently the time is 9 47. i want to schedule a reboot after 15 minutes that is 10 o'clock so i will use the at command to schedule a reboot the command is at 10 am today after that press enter it will take you to the at prompt so that we can give the commands needed to schedule the reboot so i can type the command reboot here after that press enter if you want to save this at job we need to press ctrl d this will save the at job so if you want to see whether it has been successfully saved or not the command is atq atq will show all the cues in at so after running this command it will give you the output at 10 a.m as a scheduled job so in this way we can see what jobs are existing in the at queue so we have scheduled a reboot at 10 am so we can see the cues in at jobs by running the command atq and at dash l so if you want to remove this at job the command is atrm and we need to type the job id here the job id is 2. so type the job id and press enter by running this command the job id 2 has been successfully deleted so to check whether it has been successfully deleted or not just run the command atq job 2 has been successfully deleted in this way we can create scheduled jobs by using the command at and we can delete scheduled jobs by running the command atrm now we will discuss a different way to schedule jobs by using at and after that type now so if you want to schedule a job after five minutes just type plus five minutes if you want to schedule it for after five hours just type five hours after that press enter so it will go to the at prompt and i want to shut down the machine after five hours you can type the command shutdown so if you go to the at prompt we can type whatever commands we require at that time after that press enter so to save this at job just press ctrl and d job3 has been successfully saved to check whether this job has been successfully saved or not the command is atq and we can see job3 has been successfully saved and it has been scheduled for 251. in this way we can schedule jobs by using at so to remove this job the command is atrm and the job id here the job id is three in this way we can create scheduled jobs by using the at command the service for the add command is atd so to check whether this service is running or not just run the command service atd status it will tell you the port whether at status is running or not so currently the at service is running so we can utilize the at command next we will discuss how to schedule jobs through cron tab the crontab command executes automatically according to the scheduler this crontab file executes repeatedly so there is a main difference between cron tab and at cron tab will execute the command repeatedly to schedule a job using crontab the command is crontab e after that it will take you to a text editor here we need to type what needs to be scheduled first will be the minutes from 0 to 59 so i will type 15 for 15 minutes the next column is hours so i will type 10 for 10 o'clock after that the day of the month i need this job to repeat daily so for that i need to type the asterisks after that the day of the week again i need this job to run daily so i will type an asterisk so the first one is minutes the second one is hours the third one is day of the month the fourth one is month of the year the fifth one is day of the week and after that reboot so this job will schedule a reboot every day at 10 15 am so after that save this file and in this way we can edit crontab so if you want to see the crontab details the command is crontab l it will output what has been scheduled so here we have scheduled every day at 10 15 am a reboot to occur currently the time is 10 o'clock so this box will reboot after 15 minutes in this way we can edit scheduled jobs by using the cron tab command if you want to remove these entries just run the command crontab e and just delete this line after that save the file in this way we can delete the scheduled jobs by using crontab after that you can check whether the scheduled jobs have been deleted or not by running the command crontab l currently there are no scheduled jobs in crontab in this way we can create new scheduled jobs and delete the scheduled jobs the service for crontab is service crond status so the service for crontab is cron d you can check whether the service cron d is running or not by running the command service cron d status in this way we can create scheduled jobs by using the at and crontab command next we will discuss process management to list all currently active processes on the local machine the command is ps so by running this command we can get all currently active processes on this machine press enter so these are all the processes that are currently active on the machine to know all the processes that are running by all the users the command is ps dash aux by running this command it will show you all the processes that are running by all the users on this machine just press enter so in this way we can get all the processes listed that are running by all the users [Music] in this lesson we will discuss backups and restores backups and restores are very essential in case of data damage so we need to take backups of important data daily or weekly it will help you to restore data in case of critical situations there are two types of backups in linux the first one is file backups and the second one is entire file system backup first we will take a look at how to backup files the command is tar the tar command is used to take backups of files for example just check which directory you are currently in currently we are working under root home directory so just check the files that are present in this directory by running the command ls lai so i want to take a backup of all the files and directories under this path and the command is tar cvf here we need to give the destination path i'm using the destination path in the same directory and i will use backup as my file name so in order to backup all the files and directories in this path just type star in this way we can backup all the files and directories under this path and press enter so in this way we can take backups of entire files and directories in this path let's check whether the backup file is available or not in this path here is the backup file that exists to see whether the backup has been successful or not type tar tvf backup it will give you the list of files and directories that have been backed up so we can see what the files and directories are that have been backed up in this file so in this way we can see what the files and directories are that have been backed up so if you want to restore these files the command is tar xvf backup dot so by running this command we can restore all the files and directories under this path i want to restore all the files and directories into the restore directory first create the restore directory after that cd to restore after that run the command to extract from backup the command is tar xvf and give the entire path slash root slash backup and press enter it will restore all the files and directories to restore check whether it has been successfully restored from backup or not by running the command ls-lai and we can see all the files and directories have been successfully restored from the backup file in this way we can backup particular files and directories and restore all the backed up files to a particular path so tar is the command to backup and restore files and directories next we will check out the command cpio cpio is the command used to copy files from one place to another cpio backup occupies less space compared to tar so let's try to back up all the files and directories under this path using cpio first remove the backup that was created using the tar command we will try to back up all the files and directories under this path using the cpio command the command to backup files using cpio is ls pipe cpio dash ovcf dash o backup it will backup all the files in this path after that press enter so it will backup all the files and directories in this path so to check whether it has been successfully backed up or not the command is cpio dash itvf dash i backup so we can see all these files and directories have been successfully backed up so to restore all these files the command is cpio icvf dash i backup want to back up all these files under the restore directory so i will create a new directory restore so i will try to restore all these files using the command cpio icvf dash i backup but first we need to cd to the restore directory and then run the command to restore all the files and directories the command again is cpio dash icvf dash capital i backup so by running this command all the files will restore to the restore directory so we need to give a full path here slash root slash backup so in this way we can backup all the files to a particular path you can check whether it has been successfully backed up or not by running the command ls-lai and we can see all the files and directories have been successfully backed up to the restore directory [Music] in this lesson we will discuss how to add an ip address and hostname to a linux machine we can add an ip address from the gui as well as from the command prompt let's see how to add an ip address from the gui just click on system go to preferences and click on [Music] in this lesson we will discuss se linux se linux is security enhanced linux it is an implementation of a mandatory access control mechanism this mechanism is in the linux kernel checking for allowed operations after standard linux discretionary access controls are checked in red hat linux there are three modes of selinux they are enforcing permissive and disabled let's see what a configuration file is for sc linux and how to set these modes in linux after installing red hat linux by default se linux is in enforcing mode to check the mode of selinux the command is get enforce by running this command we can get the current mode of selinux so currently se linux is in enforcing mode to change from enforcing to permissive mode the command is getforce 0 0 is for permissive to change the mode of selinux the command is set enforce zero zero for permissive so by running this command se linux will be set to permissive mode so we have successfully set sc linux to permissive mode you can check whether this permissive mode has been successfully updated in the system or not by running the command get enforce and we can see permissive mode has been successfully set in this machine to work on disk quotas ftp nfs samba and other servers without errors we need to disable se linux the main configuration file for se linux is etc slash sysconfig slash se linux this is the main configuration file for se linux from here we can see what the modes and what the selinux types are we can see enforcing permissive disabled so to work without errors on disk quotas ftp and many other servers we need to disable se linux se linux is implemented for security if se linux is in enforcing mode and you are practicing disk quotas ftp nfs samba and many other servers it will give an error in order to get rid of these errors we need to disable se linux so you can practice well on disk quotas ftp nfs samba and many other servers here i will show you how to disable se linux after sc linux so [Music] in this lesson we will discuss how to connect remote hosts or machines through the command prompt as well as the gui first we will check how to connect the remote machine through the command prompt to connect to a remote server the command is ssh and the ip address of the remote host here i will connect to the client machine and the client machine's ip address is 192.168.80.11. after that press enter we need to give the root password here after entering the password we can connect to the client machine here we can see the client machine hostname after connecting to the client machine through the ssh command if you want to come out from the session just type exit in this way we can disconnect from the remote host or machine in this way we can connect remote hosts through the ssh command ssh is very secure to connect remote hosts or machines from the command prompt this ssh command is very useful for different administrative tasks in red hat linux next we will see how to connect remote servers through putty in a windows host just open putty in the windows host after that select ssh here after that enter the ip address of the client machine so here the client machine ip address is 192. after that click open it will open a window here you need to give the root password or whatever user you want to log into the machine after that press enter it will ask for the password just enter the password for root user after that press enter [Music] in this lesson we will discuss ftp server ftp stands for file transfer protocol it's a file server to share files under heterogeneous operating systems heterogeneous operating systems means through ftp we can share files between linux to windows linux to mac mac to windows windows to linux we can share from one operating system to another operating system so an ftp server is very useful to share files between different operating systems this service is mostly used on the internet to upload and download files next we will discuss what are the port numbers for the ftp server port number 20 is used for ftp data transfer and port number 21 is used for ftp control connection next we will discuss how to configure an ftp server on red hat linux the package for an ftp server is vs ftpd first check whether this package has been installed on the server or not by running the command rpm q v s f t p d star by running this command we will see whether the ftp package has been installed or not on the server press enter and we can see that the vsf tpd package has not been installed on this machine so we need to install the vsf tpd package to run the ftp server for that we need to install the vsf tpd package we can install this package from the dvd of red hat linux i have copied all the packages from the dvd drive to rpms i've copied all the red hat packages under rpms packages from here we can see all the red hat linux packages these are all the red hat linux packages so we need to install vsf tpd here so to install vsf tpd the command is rpm dash ivh vsf tpd and in this way we can install the vsf tpd package on the linux machine we can install packages [Music] in this lesson we will discuss how to add ftp users and securing the ftp server in order to add an ftp user on an ftp server the command is user add it is the same command to add normal users on a linux machine all users on an ftp server are ftp users so here i am typing user add ftp user after that i will give the password for ftp user after adding ftp user we will check whether this ftp user can log in from the client machine through ftp so i will go to the client machine now from here i will log into the ftp server as ftp user after entering the ftp server just press enter here you will need to type the ftp username earlier we created the user ftp user after that press enter and give the password for ftp user so the login has been successful in this way we can add ftp users on the ftp server basically all users on the ftp server will act as ftp users from here we will check whether the ftp user can see ftp pub files cd rpms and ls so the ftp users can see all the files under var ftp pub to download a file from the ftp server first we need to cd to that path and after that we need to select a file to download so here i will download the readme file so for that the command is get readme so in this way we can download any file from the ftp server through the command prompt so [Music] in this lesson we will discuss package administration so how do you install rpm packages on a linux machine and other clients we can install packages through root commands that is through rpm and the other command which is yellow dog updater so first we will look at how to install packages by using the rpm command so first we need to go to the cd after that we need to go to packages so just run the ls command these are all the packages that are listed on the dvd to install any package just run the command rpm dash ivh so here i will try to install vsf tpd after that dash dash force force is used to install packages forcefully dash dash aid aid means along with dependencies so it will check any dependencies that are required for the vsf tpd package run the command and in this way we can install a package through the dvd if you want to upgrade any package just run the command rpm uvh and the package name press enter and in this way we can update a package so to update a package the command is rpm uvh and the package name in this way we can update a package through the rpm command to check whether a package has been installed or not just run the command rpm dash q vsf tpd so if it gives an output the package has been successfully installed on the machine so to check if any package is installed on the machine or not the command is rpm dash queue and the package name in this way we can know whether the package has been installed on the machine or not to uninstall a package the command is rpm dash e package name so i am using the option dash dash node depths so this will uninstall the package without dependencies after that press enter so by running this command that package has been successfully uninstalled let's check whether the package has been successfully uninstalled or not by running the command rpm queue vsf tpd that package is not installed on this machine in this way we can uninstall a package from the linux machine by using the rpm command we can install a package update a package and remove a package next we will check how to install a package through yum yum stands for yellow dog update manager to work with yum first we need to install the vsf tpd package check whether the vsf tpd package has been installed so here i will install the vsf tpd package on the server machine you can check whether the vsf tpd package has been installed or not on this server rpm dash queue vsf tpd enter so the vsf tpd package has been installed on this server after that we need to install rpm create repo create repo is a package which is used for the yellow dog update manager check whether create repo has been installed or not create repo has been successfully installed if create repo is not installed on this machine just install create repo by running the command rpm ivh create repo we require vsf tpd and create repo packages to run yum next we need to copy all the packages from the dvd to var ftp pub so i will go to the dvd directory here after that i will copy packages to the folder var ftp slash pub by running the command cp dash rf packages so i will copy all these packages to var slash ftp pub in this way we can copy all the packages to var slash ftp slash pub after copying all the packages to var slash ftp pub we can create a new repository for yum after copying all the packages to var ftp pub just cd to var ftp pub check whether the packages have been properly copied under var ftp pub by running the command ls and we can see that the packages folder has been successfully copied under var ftp pub after that run the command create repo to create the new repository under var ftp pub to create a new repo the command is create repo dash v and the path so here i am using the path var ftp pub after that press enter it will create a new repository for the packages that have been copied from the dvd to var ftp pub in this way we can create a new repository for the linux machine these are all the packages that were copied from the dvd to var ftp pub [Music] in this lesson we will discuss the nfs server nfs server stands for network file system server it is a file server to share files under homogeneous operating systems homogeneous operating systems are nothing but the same type of operating system for example this server is used to share files in the same environment if the environment is using red hat linux this nfs server will be used to share files across these machines rpc stands for remote procedure call it is used to share files between linux environments this nfs file system uses remote procedure call to share files between linux environments next we will proceed with port numbers the port number for this nfs server is 2049 2049 is the default port number for an nfs server next we will discuss how to configure an nfs server on the red hat linux machine first we need to install nfs on the server side by running the command yum install nfs star this will install all nfs related packages and press enter by running this command it will install all the packages that are related to nfs press y to proceed further so in the server [Music] in this lesson we will discuss how to secure network file system and how to mount network file system permanently on the client machine just go to the configuration file on the server side etc exports the remote directory can mount only on the client machine with ip address 192.168.a with read write and sync permission so now we will check whether this remote directory can mount on a client machine with a different ip address so save and quit this file run the export fs command the remote directory can mount only 192.168.80.11 so now we will check whether a client with a different ip address can mount this remote directory or not go to the client machine and check what the ip address is of this machine ifconfig a so this machine's ip address is 192.168.80.12 so now we will try to mount that file system on this client machine first run the show mount command on this client machine show mount e 192.168 so we can see the shared remote directory try to mount the shared directory in this client machine with a different ip address mount t nfs 192.168.80.10 colon slash remote so i will try to mount this file system under the nfs directory and it will give us an error access denied by the server while mounting so in this way we can secure the network file system just update this ip address and check whether we can mount this file system so i will change the ip address for this machine to 11 and i will try to mount the nfs file system on this client machine so i have changed the ip address of this machine now we need to restart the service network now check the ip address of this machine by running the command ifconfig dash a and we have changed the ip address of this client machine to 11. now try to mount the nfs path first check the command show mount e and the nfs server ip address so now try to mount this remote path on the client machine by running the command mount dash t nfs 192.168.80.10 colon slash remote slash nfs now we have successfully mounted this file system under the nfs path check whether it has been successfully mounted or not by running the command df-h and the remote directory has been successfully mounted under the nfs directory check the files under this nfs directory with ls lai so in this way we can check your network file system we can specify a particular client machine in the configuration file so that only that client machine can mount the nfs file system next we will discuss how to make this file system permanent on the client machine for that we have two ways one is we need to edit in etc fs tab and we need to specify here 192.168.80.10 colon slash remote and mount point nfs the file system type is nfs defaults 0 zero after that save this etc fs tab and quit so in this way we can make the nfs file system permanent on the client machine we have another way to make this mount point permanent on the client machine which is indirect mapping also called auto fs first check whether the auto fs package has been installed on this machine or not by running the command yum list auto fs so auto fs has been successfully installed on this client machine have two configuration files for this auto fs that is vi etc auto dot master this is the configuration file for auto fs and here we can see that misc is specifying auto.misc in auto.misc we need to specify the network file system path just quit this file and go to etc auto dot misc here you need to specify the nfs file system here we need to specify the mount point so here i am specifying the mount point as ram and the file system type is nfs and we need to specify nfs file system path that is [Music] in this lesson we will discuss samba server samba server was first introduced by andrew trigel in the year 1991 samba server is used to share files and printers under heterogeneous operating systems that is we can use samba to share files and printers across windows and linux machines the port numbers of the samba server are 137 netbios name service 138 netbios datagram service and 139 netbio session service so the port numbers for samba server are 137 138 and 139 now we will see how to configure the samba server in the red hat linux machine first install the package by running the command yum install samba and star press y to proceed further so we have successfully installed samba on this server you can check whether samba has been successfully installed or not by running the command yum list samba star so samba has been successfully installed on this machine the configuration file for samba is vi etc samba slash dot smb.conf so [Music] in this lesson we will talk about samba server security the main configuration file for samba server is etc samba smb.conf from here we can edit all the security settings for the samba server first the main settings for the samba server is global setting in global setting we can give a work group name and the server string so here the work group name is given as my group and the server string is nothing but to display the header of the samba server here i'm using the samba server version so if you log into the client machine it will show the samba server version as the server string so in the global settings we can edit the workgroup and server string in the server string we can type whatever line we want for example if you want to edit the server string to say this is my server the same line will be displayed in the client machine as well this is my server so this header will be displayed on the client machine when you connect to this samba server in this way we can edit server string and workgroup in the global settings next we will discuss logging options by default the log file will be saved under var log samba so all the log files will be saved under var log samba and the default size for the log file is 50 kilobytes if you want to increase that log file to 100 kilobytes we can edit the maximum log file size to 100 in this way we can increase the log file size to 100 kilobytes next we will discuss standalone server options standalone server options are nothing but how to add a samba user to the samba server so in the previous lesson we discussed how to add a samba user to the samba server using smb password so smb password has been used to add samba users in the samba server next we will discuss domain members options if the samba server is related to any domain we can edit security of that domain by giving the domain name password of the server etc so if you have a domain we can edit these options next we will discuss shared definitions we can share files and printers using a samba server by default all user home directories have been shared by samba server if you don't want to share a user's home directory through the samba server we can comment these lines by giving the colon option in this way we can disable home directory sharing in the samba server next we will discuss printers these are all the lines for printer configuration printers is nothing but what the share name is of the samba server so here we can see the printers these printers are nothing but the share name which has been specified in the samba server next we can see comment what is the comment for the samba share is printers the spool files are saved under the path var spool samba so here we can specify a different path for spool if you want browsable if any user wants to browse the printers we can give this option as yes if we don't want the user to browse these printers we can give the option as no if any guest wants to use these printers we can give this option as yes if you don't want guest users to use these printers we can give it as no if these printers were enabled for printing we can give it as yes if you don't want to use these printers for printing we can put no in this way we can secure the printers on the samba server next we will discuss how to secure shares in samba server these are all the configurations which have been specified in the samba server smb share is the share name so here we are going to use the share name as smb share and the comment is ftp share so we are sharing var ftp pub using this samba server so the path has been given as var ftp pub if any users want to use this path we can give this as yes if you don't want to enable every user to use this path we need to say no writable the writable option is given if you want to enable any user to edit files if you want to enable users to edit files under var ftp pub type yes if you don't want any user to write files under var ftp pub we need to type no so in this way we can secure files that have been shared using samba server after that save this file and quit after editing the samba configuration file we need to restart the samba server by running the command service smb restart so in this way we can restart the samba server and check how the shares have been shared in the client machine so i will go to the client machine here after that run the command smb client dash l samba server ip address and after that dash n this command will give you the brief description of the samba shares and printers that are being shared by the samba server after that press enter here we can see smb share so smb share which has been shared ftp share these are all the printers which have been shared by the samba server workgroup is workgroup so these are all the details about the samba server which have been shared by the samba server so we can see all the details from the client machine in this lesson we learned how to secure samba server using the samba configuration file in the next lesson we will discuss dhcp thank you so [Music] in this lesson we will discuss the dhcp server dhcp stands for dynamic host configuration protocol it is a standardized networking protocol used on ip networks that dynamically configure ip addresses and other information that is needed for internet communication dhcp allows computers and other devices to receive an ip address automatically from a central dhcp server it reduces the need for a network administrator or a user from having to configure these settings manually dhcp gives ip addresses automatically to clients it will prevent ip conflicts as well what are the port numbers for the dhcp server the port numbers for the dhcp server are 67 for boot p 68 for dhcp so there are two port numbers for the dhcp server 67 and 68. next we will talk about how to configure the dhcp server on a red hat linux machine in order to proceed with the dhcp server first we need to install the package on this linux machine for that we need to run the command yum install dhcp star after that press enter it will automatically install all the dhcp related packages on this linux server press y to proceed further this command will install all the dhcp related packages after installing we can check whether the dhcp package is installed or not on this machine by running the command yum list dhcp star now we know that the dhcp package has been successfully installed on this machine next we will proceed with the configuration of dhcp to proceed with dhcp configuration we need to copy a sample configuration file from slash usr so first we need to go to slash usr slash share slash doc after that we need to go to dhcp from here we need to copy the dhcpd configuration file to slash etc dhcp the command to copy this configuration file is cp dhcpd.conf dot sample and we are copying this file to slash etc dhcp slash dhcpd.conf after that press enter in this way we need to copy the sample configuration file to slash etc dhcp after that press enter so we have successfully copied the configuration file for the dhcp server we can go to cd slash etc dhcp directory from here we can edit the main configuration file for the dhcp server that is dhcpd.conf this is the main configuration file for the dhcp server from here we can edit dhcp settings so this is the main configuration file for the dhcp server these two lines will specify default lease time and maximum lease time for an ip address which has been assigned to a client machine so the default lease time will be 600 maximum lease time is 7200 if we want more default lease time and maximum lease time we can edit it here so i want to increase the default lease time to hundred so i have changed it to sixteen hundred in this way we can edit default lease time and maximum lease time for a dhcp server next we will discuss subnets these two lines are the main important lines for a dhcp server so i will provide the subnet here it is 192.168.80.0 and the net mask value is 255.255.255.0 i want the client machine to automatically get the ip from the dhcp server in the subnet value of 192.168.80.0 after that we need to specify the range so here i will specify the range as 192.168.80.15 to 192.168.80.20. so here the range of the subnet has been defined from 15 to 20. so the client machine will get any ips from this range after editing the subnet netmask and range details we can save this file and we will test whether the client machine is taking the ip address in this range or not i will save this file and quit and i will check in the client machine whether the ip is being taken from this range or not after editing the dhcp configuration file we need to start the dhcp server on this red hat linux machine the command to start the dhcp server is service dhcpd start so in this way we can start a dhcp server on the server machine now i will check in the client machine whether the ip address is being taken automatically or not from the dhcp server i will go to the client machine here after that i will go to network connections and i will select eth0 edit and i will go to ipv4 settings and here i will select automatic dhcp after that click on apply and here we need to give the root password so i typed the root password after that we need to start the network service on the client machine so here i'm restarting the network service so now check the ip address on this machine by running the command if config dash a so we can see the new ip address that was assigned from the dhcp server so the new ip address that was assigned is 192.168.80.15. which we had specified in the range on the dhcp server in this way all the client machines automatically get ip addresses from the dhcp server so the dhcp server is very useful when we are installing an operating system on a remote host so the client machine will automatically get an ip address in that range and install the operating system in the client machine so in this way we can configure the dhcp server on the server side as well as on the client side next we will discuss how to assign specific ip addresses for the client machines for example this client machine requires a specific ip address that is 192.168.80.88 so how can we set this up in the dhcp server first we need to note the mac address of this client machine here is the mac address of the client machine it is 0 0 colon 0c colon 2 9 colon d9 colon 2f colon da so after noting this we need to add this mac address in the dhcp server so that every time this client machine will get the same ip address so for that we need to go to the server [Music] in this lesson we will discuss nis server nis stands for network information service the network information service or nis was originally called yellow pages or yp it is a client server directory service protocol for distributing system configuration data such as user and host names between computers on a computer network sun microsystems developed nis the technology is licensed to virtually all other unix vendors nis is a type of authentication service which provides remote authentication to normal users in the network this mechanism provides centralized login to the normal user between linux to linux nis works on a random port number next we will see how to configure this nis server on a red hat linux machine b [Music] in this lesson we will discuss the dns server dns stands for domain name system it is a hierarchical distributed naming system for computers services or any other resource connected to the internet or a private network it associates various information with domain names assigned to each of the participating entities most prominently it translates easily memorized domain names to the numerical ip addresses needed for the purpose of locating computer services and devices worldwide by providing a worldwide distributed keyword based redirection service the domain name system is an essential component of the functionality of the internet a dns name server is a server that stores the dns records for a domain name such as an address a or aaa records name server ns records and mail exchanger mx records a dns name server responds with answers to queries against its database next we will discuss how dns works this is the domain name system so in this way dns has been hierarchically distributed for example if you are trying to get myexample.org it will resolve from ip to name and the name to ip address so how does this name resolve in dns in this diagram it tells us we are looking for mail.example.org so first it will resolve the ip address after that it will resolve the name server in this way dns will resolve ip addresses and name next we will discuss what the dns records are there are many types of dns records so we will discuss dns records here canonical name a canonical name is used to define an alias hostname a record an a record gives you the ip address of a domain that way when users try to go to www.example.com it will get to the right i p address an a record or address record maps a hostname to a 32-bit ipv4 address mx record or mail exchange record mail exchange records map an existing domain name to a list of mail exchange servers for that a domain can have one or more mail exchange records these records point to hosts that accept mail messages on behalf of the host a host can be an mx for itself mx records need not point to a host in the same zone ptr record or pointer record maps an ipv4 address to a canonical name for that host setting up a ptr record for a host name in the in addr dot arpa domain that corresponds to an ip address implements reverse dns lookup for that address for example at the time of this writing www.ican.net has the ip address of 192.0.34.164. but a ptr record maps 164.34.00 dot in addr dot arpa to its canonical name ns records or name server records oh [Music] in this lesson we will discuss more about dns to check all these configuration files so we have configured named.conf rsc.1912.zones and forward and reverse lookup zone files so we have configured four major files for dns to check these configuration files the command is named dash check conf this command will check the configuration files now i will check etc named.conf so by running this command it will check whether this configuration file is looking good or not if there are any errors in the configuration file it will give you the output otherwise it won't give any output this configuration file has no errors next we will check rfc.1912.zones use the same command which is named dash check conf slash etc slash named dot rfc1912.zones i will run this command to know if there are any errors in this configuration file and currently there are no errors in this configuration file next we will check forward lookup zone file and reverse lookup zone file for that the command is named checkzone named checkzone will check the configuration file for forward and reverse lookup zone files so i will check first for forward lookup zone file the syntax for named check zone is named check zone after that we need to specify the dns domain that is example.com after that forward lookup zone file example.4 if the configuration looks good it will give ok as the output otherwise it will give errors so we can see this configuration file has no errors now we will check for reverse lookup zone file named check zone after that we need to specify the reverse ip address here that is 80.168.192 dot in addr dot arpa [Music] in this lesson we will discuss the apache server apache otherwise known as apache http server is an established standard in the online distribution of website services which gave the initial boost for the expansion of the world wide web it is an open source web server platform which guarantees the online availability of the majority of the websites active today the server is aimed at serving a great deal of widely popular modern web platforms and operating systems such as unix windows linux solaris novell netware freebsd mac x microsoft windows os 2 etc next we will discuss the port numbers of the apache server the port number for the apache server is 80. next we will discuss how to configure this apache server in red hat linux in order to work with the apache server first we need to install the apache related packages on this linux server for that we need to run the command yum install http star http is the package for the apache server so i am installing apache related packages on this linux machine after that press y to proceed further b [Music] in this lesson we will discuss kickstart installation the red hat kickstart installation method is used primarily but not exclusively by the red hat enterprise linux operating system to automatically perform unattended operating system installation and configuration a kickstart file contains a series of options to be passed to the anaconda installer that describes how to set up the system it may also include custom scripts to be run before or after the installation next we will discuss how to create a kickstart installation file and how to install red hat linux on the client machine by using kickstart in order to proceed with kickstart installation first we need to install the kickstart package for that the command is yum install system dash config dash kick star so in this way we can install all the kickstart related packages on this linux server after that press enter to proceed further press y to proceed with the installation in this way we can install the kickstart related packages on this linux server so all the kickstart related packages are being installed on this linux server so we have successfully installed all the kickstart related packages on this server now we will proceed with configuration of kickstart for that the command is system dash config dash kickstart after that press enter to proceed further a pop-up window will appear from here we need to select all the options for the kickstart file here i will start from basic configuration in the basic configuration window we need to select the default language here i will select the default language as english keyboard type as us english time zone i will proceed with american time after that the root password we need to type the root password here so we have chosen all these configuration settings in the basic configuration next we will proceed with installation method in the installation method we will select ftp method so here we can specify the ftp server that is 192.168.80.10. the ftp directory is pub after that we will proceed with the bootloader options in the bootloader options there is no need to change any options next we will proceed with partition information in the partition table we can edit the partition settings so i will add the partition settings here root i will add 10 gigabytes of space after that i will add for boot 250 megabytes of space so i have added root and boot after that i need to add swap for swap i will add 2048 that is 2 gigabytes after that press ok to proceed further so we have added root boot and swap after that we will proceed with network configuration so in the network configuration window we can add a network device so here i will add the network device as eth0 network type is dhcp after that press ok after that authentication and i will keep the default settings in authentication in firewall settings i will disable se linux after that in display configuration i will make it default in the package section i will also keep that as default for pre-installation script if we have any scripts we can add that script here but i am not using any scripts after installation if you want to run any post installation script we can add that post installation script here in this way we need to create a kickstart file after that save this file and quit this window in this way we can create kickstart files for kickstart installations so we have successfully created a kickstart installation file now i have rebooted the client machine with the red hat dvd after entering this screen we need to press tab here we need to type repo equals ftp colon slash slash and the ftp server ip address which is 192.168.80.10 after that press enter and after that it will proceed with installation from the network after that we need to select dhcp for ipv4 and after that it will proceed with the automated red hat installation in this way we can install remote client machines by using kickstart files in this lesson we learned what kickstart installation is created a new kickstart installation file and installed red hat linux on the client machine by using the kickstart file thank you so in this lesson we will discuss send mail send mail is a general purpose inter-network email routing facility that supports many kinds of mail transfer and delivery methods including the simple mail transfer protocol smtp used for email transport over the internet the port number for send mail is 25. next we will discuss the basic sendmail configuration in red hat linux in order to work with sendmail first we need to install the sendmail packages on the linux server for that the command is yum install send mail star after that press enter to install the send mail packages on this linux server press y to proceed further we have successfully installed send mail on this linux server now we will proceed with configuration the main configuration file for send mail is etc mail send mail dot mc this is the main configuration file for send mail so here i'm not editing any configuration in this file i will quit from this configuration file after that we need to run the command make dash c slash etc mail by running this command it will convert the configuration file sendmail.mc to sendmail.cf so it will convert from a normal configuration file to a macro language configuration file so we have successfully created a macro file the macro file is slash etc mail slash sendmail.cf this is the macro configuration file for sendmail so if you want to update any configuration file first we need to update it in sendmail.mc so here we need to edit the configuration after that we need to save this file and run the command make dash c etc mail so it will convert normal send mail configuration to a macro configuration file so this is how you edit configuration files in sendmail after configuring the configuration file for sendmail we need to restart the service that is service send mail start in this way we need to start the sendmail service on the linux server so we have successfully started sendmail on the server now we can send mail from this server in this linux server we have configured sendmail with default settings now we will see how to send mail using sendmail so first check whether send mail is running or not on this linux server the command to check whether the send mail service is working fine or not is service send mail status so currently send mail is running on this linux server now we will send a few mails to other users on this linux server for that the command is mail dash v v for verbose dash s s is for subject so here we need to specify the subject i will specify the subject as test mail after that we need to give an email address i will send this mail to steve at server.example.com so in this way we can send mail from one user to another user after that press enter after entering this command we will enter into the edit prompt here we can edit the message of the email so i will edit this email as this is my test mail after that press enter so after editing this message press control d to send this email to steve at server.example.com so i will press ctrl d here and from here we can see this mail is using send mail so it is sending from calion at server.example.com to steve at server.example.com now we will check whether this message has been sent to steve or not first we need to switch users to steve after that run the command mail so by running mail it will show all the mails for the user steve so these are all the mails for steve and we have sent test mail here and we can see the details by pressing the number here the number for this mail is five so after that press enter to see the details for this mail so i have entered five to check the email details and we can see it came from calyan at server.example.com to steve at server.example.com with the subject test mail and the message is this is my test mail if you want to come out from this command press q so in this way we can check whether email has been delivered or not to the respective user in this way we can send emails between users on the linux server by using sendmail in this lesson we learned what sendmail is and the default configuration for sendmail and how to send and receive emails on a linux server by using sendmail thank you [Music] so [Music] in this lesson we will discuss raid raid stands for redundant array of independent disks it is a storage technology that combines multiple disk drive components into a logical unit for the purposes of data redundancy and performance improvement data is distributed across the drives depending on the specific raid level next we will discuss the raid levels first raid 0. raid 0 comprises striping but no parity or mirroring it improves performance but does not add redundancy and does not improve fault tolerance any drive failure destroys the array and the likelihood of failure increases with more drives in the array raid 1 raid 1 comprises mirroring without parity or striping data is written identically to 2 or more drives thereby producing a mirrored set the read request is serviced by either of the two drives containing the requested data this can improve performance if data is read from the disk with the least seek latency and rotational latency conversely write performance can be degraded because both drives must be updated thus the right performance is determined by the slower of the two drives the array continues to operate as long as at least one of the drives is functioning next we will discuss raid 5. raid 5 comprises block level striping with distributed parity parity information is distributed among the drives it requires that all drives but one be present to operate upon the failure of a single drive subsequent reads can [Music] in this lesson we will discuss iptables iptables is a rule-based firewall which will process each rule in order until it finds one that matches by using iptables we can allow or block specific ip addresses or port numbers in linux iptables is a powerful firewall built into the linux kernel now we will see how iptables work on red hat linux to check the current iptable's rules the command is iptables b [Music] in this lesson we will discuss virtualization virtualization is a broad computing term used for running software usually multiple operating systems concurrently and in isolation from other programs on a single system most existing implementations of virtualization use a hypervisor a software layer or subsystem that controls hardware and provides guest operating systems with access to the underlying hardware the hypervisor allows multiple operating systems called guests to run on the same physical system by offering virtualized hardware to the guest operating system next we will look at packages for virtualization install the below packages for virtualization on red hat linux these packages will be available only on the 64-bit os so these below packages need to be installed on red hat linux in order to work with virtualization next we will discuss different types of virtualization on red hat linux there are various methods for virtualizing operating systems the first one is full virtualization full virtualization uses the hardware features of the processor to provide guests with total abstraction of the underlying physical system this creates a new virtual system called a virtual machine that allows guest operating systems to run without modifications the guest operating system and any applications on the guest virtual machine are unaware of their virtualized environment and run normally hardware assisted virtualization is the technique used for full virtualization with kvm kernel based virtual machine in red hat enterprise linux the second one is para virtualization virtualization employs a collection of software and data structures that are presented to the virtualized guest requiring software modifications in the guest to use the power virtualized environment power virtualization can encompass the entire kernel as is the case for zen para virtualized guests or drivers that virtualize io devices so [Music] in this lesson we will discuss certification preparation first i will talk about practice environment create a practice environment with at least two network machines and begin practicing virtual machines in vmware will suffice for this configure each service and test it secure it so it cannot be accessed by untrusted systems practice all the topics practice well on all the topics and get detailed knowledge on each topic next i'll talk about exam environment format of the rhce exam the rhce exam is a hands-on practical exam that lasts two hours internet access is not provided during the exam outside materials are not permitted documentation that ships with red hat enterprise linux is available during the exam so man pages will work so if you want help you can get it from the man pages time management answer questions one by one on the exam and manage the time well during the exam in this way you can achieve the best score on the rhce exam in this lesson we have discussed how to prepare for certification and the exam environment thank you and all the best you