Matt,
We do a full backup once a week and incrementals every other day.  Our full
backups take about 2 hours and the incrementals only take an hour or less
depending on the activity for that day.  If you don't save any time by
doing the incrementals then you are better off doing fulls.  It takes less
time to restore the database from a full than using incrementals.  When we
first started using incrementals I had it set up to do 30 incrementals and
then a full.  Wouldn't you know on day 29 we lost the database and I had to
restore using 30 tapes.  That's when I changed it to weekly.
Jim Sporer

  At 10:49 AM 3/13/2003 -0500, you wrote:

I'm curious about the type and frequency of database backups that
people do.  I've inherited a TSM environment set up by sombeody else
and I'm trying to make sense out of it.

The original setup did two backups every day, a full and a snapshot.
The full stayed onsite and the snapshot went offsite.  (We use DRM,
and the MOVE DRM * SOURCE=DBS sent the snapshot offsite and left the
full alone).  That seemed like overkill, so I changed the "onsite"
backup to do a full backup on Sunday and an incremental other days.
But at two hours for a full backup, and almost as long for an
incremental, I'm wondering if we're still spending more time than
necessary backing up our database.  Does anybody else see the need
for two daily backups?  I think the likeliihood of a disaster
requiring a database restore is so slim that a single offsite copy
might be enough, especially since our "offsite vault" is less than a
5-minute walk (which raises another issue, but thats what we're
living with).

Does anybody mess with full/incremental database backups? Or, if I'm
only going to do one backup a day, would it make more sense to do a
full every day, to simplify things if I do have a disaster and need
to restore?
--


Matt Simpson --  OS/390 Support
219 McVey Hall  -- (859) 257-2900 x300
University Of Kentucky, Lexington, KY 40506
<mailto:matt AT uky DOT edu>
mainframe --   An obsolete device still used by thousands of obsolete
companies serving billions of obsolete customers and making huge obsolete
profits for their obsolete shareholders.  And this year's run twice as fast
as last year's.