Air Cleaner User Manual

level should be included in the backup. Specifying level 0 indicates that all files
should be backed up. Level 0 is still considered an incremental level; it is the base
for all incremental levels that follow.
Any number of incremental levels from 0 through 9 can be used, but using too
many levels can complicate the restore process.
Consider the following incremental backup examples:
Incremental backup of a file system is performed as follows:
Monday level 0
Tuesday level 1
Wednesday level 2
Thursday level 3
Friday level 4
Saturday level 5
Sunday level 6
In this case, if you need to restore the entire file system from the backup
performed on Sunday, you must restore every single backup from 0 through 6 in
order to incrementally reapply the changes to date. Always restore level 0 first
(when restoring from scratch) because only level 0 contains a backup of the entire
file system. Then, in the correct sequence, reapply each level that follows, adding,
replacing, and removing files until the file systems return to their most recent state.
Incremental backup of all volume groups, except the rootvg group, is performed
as follows:
1st of month level 0
every Friday level 4
Monday-Thursday level 7
In this example, a volume group backup is performed on the first day of the
month. Every Friday a level 4 is performed, and every other day of the week
(excluding Saturday and Sunday) a level 7 is performed. Because only three levels
are used, no more than three backups need to be restored. If you need to restore
the entire volume group because of failure, the restore sequence would be:
1. Restore level 0.
2. Restore the most recent level 4 if a level 4 was performed since the last level 0.
3. Restore the most recent level 7 if a level 7 was performed since the last level 4
or level 0.
Note: Use care when combining both volume group and file system incremental
backups. An incremental volume group backup is identical to performing an
incremental backup of each individual logical volume and file system in the
volume group. Therefore, after performing a volume group level 0 backup,
you can perform other incremental backup levels for specific file systems. If
a level 0 backup of a file system is performed after a level 0 of the volume
group containing that file system, any higher-level incremental levels for
that file system are applied to the most recent (file system) backup.
4-2 IBM Tivoli Storage Manager for System Backup and Recovery: Installation and User’s Guide