HP 3000 Manuals HP 3000 Manuals
Choosing Types of Backup
Performing a combination of full and partial backups on a daily basis
provides you with file security. As system manager, you decide what type
of backup to use and how often to perform each one. In many companies,
for example, the system manager schedules full backups once per week and
one of two kinds of partial backups, an incremental partial backup or a
cumulative partial backup, all other days to save time and decrease media
usage.
* The purpose of a full system backup is to store your entire system
(files, data, and programs) to tape. Depending on your needs, you
will want to do a full system backup at least once a week, and
perhaps more often.
* During an incremental backup, you make a backup copy of only those
files that have been modified on or after a specified date.
Typically, this is the date of the last backup, regardless of
whether it was a partial backup or a full backup. If you back up
your system on a daily basis, each incremental tape will contain
those files updated during the last 24 hours.
* During a cumulative backup, you make a backup copy of all files
that have changed since the last full backup, so that the number
of files copied to tape accumulates. If you back up your system
on a daily basis, the first cumulative tape will contain files
updated in the preceding 24 hours, the second tape contains files
updated in the preceding 48 hours, and so on.