HP 3000 Manuals

Performing System Management Tasks

Creating a Backup Schedule 

A schedule helps ensure that backups are done on a regular basis.  You
should design one that accommodates the particular needs of your
information processing environment.  Here are three sample backup
schedules that may be helpful in designing an appropriate schedule for
your needs.

When to do full backups 

One possible backup schedule is to store your entire system to tape at
the end of each work day.  The benefit of this schedule is that in a
recovery situation, you or the system operator must handle only one tape
set.  The disadvantage is that, since all files (including those that
have not changed) are backed up every day, the amount of time and media
needed to complete the backup increases greatly.

When to use cumulative backups 

Another strategy is to perform a full backup once per week, and partial
cumulative backups on all other work days.  This strategy reduces both
time and media usage.  In a cumulative backup, the date is always the
date of the last full backup and uses the "greater than or equal" form
;DATE>=mm/dd/yy.

Following a cumulative backup stategy, you will need to handle only two
store tape sets to perform a full system recovery:  the most recent full
backup set and the most recent partial backup set.


          Figure 10-1.  Cumulative Backup Schedule 

When to use incremental backups 

In an incremental backup strategy, you perform a full backup once per
week and partial backups on all other workdays.  However, since the date
of each partial backup is the date of the last partial backup (not the
date of the last full backup), only those files which have changed are
copied to tape.

The principal advantage to the incremental backup strategy is that it
uses the smallest amount of time and media.  The disadvantage is that, in
the event of system recovery, you must restore each tape set from the
most recent full backup through the most recent partial backup.


          Figure 10-2.  Incremental Backup Schedule 

MPE/iX 5.0 Documentation