Thanks for the idea - by collocating the offsite, does that mean that you
eject one tape per node every day? Or how does the collocate happen, given
the previous tapes are offisite?

I'd love to collocate the offsite, and am reading some interesting ideas in
the maillist archives about Restore STGPOOL to up-stage the tapes to disk,
without tape contention, so everyone can start restores at the same time...

-----Original Message-----
From: David E Ehresman [mailto:deehre01 AT LOUISVILLE DOT EDU]
Sent: Thursday, 13 January, 2005 11:28
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: TSM DR Exercise Restore Ideas


We colocate onsite and offsite tapes for all of our important (in a DR
sense) nodes.  TSM runs on a dedicated machine with dedicated tape
drives.  Backups run at night.  Thus the machine and tape drives are
available all day for backup storagepool, migrate, and reclaim.  Since
reclaims are single-threaded by storagepool and we have more tape drives
than storagepools, we use a shell script to generate MOVE DATA to
reclaim the offsite tapes.  That way we can run as many at one time as
we have tape drives available.  This keeps the number of our offsite
tapes to the minimum.

David Ehresman

>>> Sulis.AJ AT FORCES.GC DOT CA 01/13/05 10:56 AM >>>
Hi All:

I am looking for suggestions to improve efficiency in our Backup
strategy:

Current:
We backup 200 nodes to a DASD diskpool (large enough for one day's
backup),
then migrate to a VTS, with an offiste copy going to 3490
(uncollocated, of
course). To improve day-to-day restores, we implemented a weekly
full-backup
for our nodes. This means that restores come from a maximum of the last
1
week's worth of tapes (only need the active versions of the files).
Also,
these full backups make our Disaster Recovery restores easier to work
with
(when we get to the DR location, we call for tapes from the past
weekend,
and all incrementals since. The problem is that we only have the
city-to-city bandwidth to offer weekly full backups to the nodes
participating in the DR plan...

Proposed:
What I would like to do is remove the VTS, have the backups direct to
DASD,
then migrate to a collocated 3490, with an offiste copy same as
before.
Having done this, we would have improved backup performace for all
nodes,
and provided great restore performance for all nodes.

Problem: Without weekly full backups, the offsite tapes required for a
restore would grow to a huge number (Operating System files would be on
a
very early tape, and every tape generated since would have incremental
data
for that node). Is there any way to make a shorter list of tapes
required
for DR? How is everyone else dealing with the offsite tapes? Again, we
are
only interested in the "active versions". I could aggressively reclaim
the
offsite pool to create newer tapes, but that's a lot of TSM thrashing
for
little gain (still cannot say to the vault "send me all tapes since
last
Saturday". Daily backupsets do not work within the DR plan, as far as I
can
tell. (Unless I can generate a backupset to remain inside TSM, which
would
get copied to the offsite daily, and still be available at the DR
site...

I must be missing a command or a concept - how is everyone else doing
this?
Any thoughts appreciated.


Adam Sulis
DNIS6-5
2nd Floor, Tunney's Pasture L002
Tel (613) 998-9093
Sulis.AJ AT forces.gc DOT ca