Greetings,
I would like y'alls input on how to handle tape rotation offsite.
The
operations group I am working with wants to be able to ship boxes of
tapes out, and get them back according to a simple rotation scheme.
This is easy to do with products like Legato or Omniback. It is a
pain to do with ADSM. They want to:
1) Check out all the offsite storage pool and ADSM DB full backup
tapes from the library on a daily basis.
2) Put them in a lock box and send them offsite.
3) After a few weeks have passed, bring the entire box back
onsite.
4) Take the tapes out of the box, and check them back into the
library as scratch tapes.
In order for this to work, all the data on the tapes must expire
before they come back onsite. Since we are doing incremental
backups (like most people do) on filesystem data, a lot of the
data remains valid on the tape when it is time to come back. Some
of the tapes contain Oracle database backups which are
archives, and they can be made to expire when we want them
to, but what about the filesystem data?
I can think of a few ways of doing this, but all of them have
problems:
1) Use offsite reclamation. The big problem here is that
there is no sure way of automating it without the offsite
storage pool tapes that happen to still be onsite getting
reclaimed before they leave. The Admin Guide's way
of handling it is to turn on reclamation on the offsite storage
pools, wait till it finishes, then turn it off again before you
check out your offsite tapes. The problem with this is that
it will cause confusion of the operators, first of all. But I
only want to reclaim the tapes that are due to come back,
not every tape in the offsite storage pool! How can I be
certain of reclaiming all the tapes that are due to come back
in a given box without reclaiming everything in the storage
pool?
2) I could always do 'delete volume' on every tape that is
due to come back. If I do it a few couple days before it
actually comes back, new copies of remaining active
data will be generated and sent offsite before the volumes
are sent back. This looks promising, but I can't see any
easy way to figure out within ADSM which tapes need
to be deleted. You can't do a "delete volume date=today-14"
or some such command, at least I can't find a way. I could
write some mechanism outside of ADSM to record the volumes
by julian date when they are checked out, then two weeks
later delete them. But that requires a bunch of date
calculations in code, and sounds error prone, especially with
Jan 1,2000 coming along. Also, it scares me to build 'delete
volume' commands into a script, since I won't be the person
to monitor whether it is working on a regular basis. What if
for some reason we went a week without getting any copy
storage pool tapes sent offsite? This script would be
merrily chugging along, deleting all our offsite tapes!
We are using DRM, which I thought might have some feature
to help us here, but it doesn't seem to. It does allow me to
automatically expire the ADSM DB backups, and also set
a reuse parm on the storage pool tapes, which makes sense,
but nothing to expire tapes.
Any clever suggestions would be appreciated.
John Schneider
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* John D. Schneider Email: jdschn AT ibm DOT net * Phone: 314-349-4556
* Lowery Systems, Inc.
* 1329 Horan Disclaimer: Opinions expressed here are
* Fenton, MO 63026 mine and mine alone.
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