Importance of Backup and Backup Strategies

Why Backups are Essential

• Backups are crucial for data recovery.
• They allow for easy and quick restoration of lost data.

Considerations for Backup Planning

• Data Volume: Determine the amount of data to back up (MBs, TBs, or more).
• Backup Type: Decide on the type of backup.
• Backup Media: Options include local tape, hard drive, or cloud.
• Storage Location: Options are on-site, off-site, or in the cloud.
• Software: Choose software for backup/restoration (third-party or built-in OS tools).
• Backup Schedule: Daily full backups, daily incremental with weekly full backups, etc.

Types of Backups

On-Site Backup

• Data and backup media are co-located.
• No need for internet or WAN for data transfer.
• Generally cheaper than off-site backups.

Off-Site Backup

• Data is stored at a different location.
• Can involve physical media transfer or network connection.
• Enables data recovery from any location.

Combination Strategy

• Use both on-site for quick recovery and off-site for long-term storage.

Snapshot Backup

• Common in virtual machines and cloud infrastructures.
• Allows quick backup with a single click.
• Functions similarly to incremental backup by saving daily changes.

Replication

• Real-time data copying to one or multiple locations.
• Provides a real-time backup and can be used for disaster recovery.

Backup Scheduling

• Frequency can vary: weekly, daily, hourly.
• Depends on data volume and system activity.
• May use multiple backup sets with different intervals.

Security and Access

• Backups can contain sensitive data.
• On-site allows controlled access.
• Off-site or cloud storage may require encryption to prevent unauthorized access.

Testing Backup Restores

• Critical to perform regular tests to ensure data can be restored.
• Simulate disasters or select databases for testing.

Journaling in Backup Systems

• Protects against data corruption due to power loss during write operations.
• Write data to a journal first, then to the database.
• Journals help recover from corruption by providing a record of data changes.