All of the blocks in a raw, or block, device get backed up during block-level backups. For supported file systems, only the blocks that contain data are backed up.
High-Level Process for Block-Level Backups
- A snap-capable volume is configured as a source volume for taking hardware or software snapshots.
- During a snap backup job, the following processes are performed:
- Snapshot creation
- Bitmap management
- A backup copy job moves the block-level snap data to any media. The backup copy job is run immediately for native engines; for non-native engines, you must explicitly enable the backup copy job to be run.
- If the primary snap copy is configured as a spool copy (a copy with no retention rules), then the snapshots are automatically deleted.
- When you select a native engine for snapshots, you cannot select a proxy for backup copy.
- If metadata collection was disabled during backup and you initiate a live browse, it will show all the files on the volume including the unchanged files. Filters are ignored.
- On AIX, only one CXBF or CVBF snap can exist for a given device.