Managing Systems and Workgroups: A Guide for HP-UX System Administrators

Administering a System: Managing Disks and Files
Backing Up Data
Chapter 6 683
Backup Levels
If you use SAM to back up your system, you do not need to know about
backup levels (because SAM will handle them for you). If you will use the
commands fbackup and frecover directly, you should read this section.
A backup level is a level you define that identifies the different degrees of
incremental backups. Each backup level has a date associated with it
that indicates when the last backup at that level was created. You can
have up to ten backup levels (0 through 9). For example, level 0 is a full
backup; level 1 backs up files that changed since the last level 0 backup;
level 2 backs up files that changed since the last level 1 backup, and so
on.
This brings up the question, “how does fbackup know when the previous
backup was created?” This information is contained in the file
/var/adm/fbackupfiles/dates, a file that is updated only when all of
the following conditions are true:
• The -u option is used with fbackup.
• A graph file is used to indicate which files should be
included/excluded when a backup is performed.
• Neither the -i nor the -e option is used (graph file used instead)
• The backup completed successfully
Backup levels are a way of specifying varying degrees of incremental
backup. For example, suppose you wanted to set up the following backup
schedule:
• On the first day of the month, back up an entire set of selected files (a
monthly, full backup).
• Every Friday, back up all files in the selected set that have changed
since the previous Friday (a weekly, incremental backup so that you
can back up and restore files that have been active within the month,
relatively quickly).
• Every day except Friday (or the first of the month), back up all of the
files in the selected set that have changed since the previous day (a
daily, incremental backup, so that you can quickly back up and
restore files that have been active within the last week).