System Administration Guide
Chapter 3, Backing up filesystems

How backups restore complete filesystems

How backups restore complete filesystems

When you restore a complete filesystem, the Backup Manager constructs a backup set consisting of the last occurrence of each backup level, in ascending order.

For example, a hardware failure ruins the data on your hard disk on Friday, the last day (Day 5) of the backup schedule, immediately before the backup scheduled to be done that evening. The following backups were performed during the week:

  1. Level 0 (Monday, Day 1)

  2. Level 1 (Tuesday, Day 2)

  3. Level 2 (Wednesday, Day 3)

  4. Level 2 (Thursday, Day 4)
The Backup Manager constructs a backup set to restore the system to the current date (Day 5). The backup set consists of the Level 0, Level 1, and the Level 2 that was performed on Day 4. You do not need to restore the first Level 2 (Day 3), because the Level 2 that was performed on Day 4 backed up all the files changed since Day 2. The only information that is missing is what was changed during the day on Friday prior to the hardware failure.

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