ADSM-L

Re: reclaim spoy stgpool volumes

2001-05-09 16:48:21
Subject: Re: reclaim spoy stgpool volumes
From: Jon Milliren <jon.milliren AT IA.PITT DOT EDU>
Date: Wed, 9 May 2001 16:30:54 -0400
Lindsay Morris wrote:
>
> The "filling" tapes are not candidates for reclamation - TSM still hasn't
> written all the way to the end of the tape yet.  Only the FULL tapes might
> be reclaimed, and the smallest one is 55.7% full, which means "upd stg xxx
> recl=44" should cause it to be reclaimed.

        Ahhhhh... I see now. (Although I hadn't considered the full/filling
before). I guess I shouldn't be so gung-ho on expecting tapes to go out
and come back. I'm wondering why reclaim didn't start when I bumped
reclaim threshold to 60? I guess because I didn't leave it that long.

> It's normal to have all your tapes about 50% used. If you try to reclaim a
> tape that is mostly full, reclamation will probably require a new scratch
> tape, so even though it frees up THIS tape, you still have no net gain in
> scratch tapes.

        I'm not too terribly concerned about freeing scratch tapes as much as
having a consistent rotation. Ideally, I'd like to have some tapes come
back as well as sent out. I guess I have to wait a few more weeks to see
how this all goes. At least I'll be able to rotate the DB backup volume
weekly.

        So if full tapes are normally around 50% utilized, should I wait until
the utilization drops to 25-30% before starting a reclaim? I imagine
I'll have to wait to see how long it takes for utilization to drop to
that level. The only reason I'm concerned about reclaim is that my
offsite charges per tape, and I have to call them the day before if I
want tapes returned.

        Thanks much for all the help!

Jon

--
Jon Milliren
Jon Milliren
Systems Administrator
University of Pittsburgh
Office of Institutional Advancement

jon.milliren AT ia.pitt DOT edu
(412) 624-2727 office
(412) 292-2070 mobile