Re: [ADSM-L] reclamation

.
Richard - it is not reclaiming anything, because you don't have any
tapes to reclaim. The script you are using that shows tapes awaiting
reclamation at 99% utilized is misleading you. That is showing you how
many tapes you could reclaim if you set the threshold to 1.

The basic prioblem is that % utilized is PERCENT FULL, while %
reclaimable (and the threshold you set on the UPDATE STGPOOL command) is
PERCENT EMPTY. It will not add up exactly, but

  (% utilized) + (% reclaimable) = 100% (approximately)

(I'm not going to go into why this does not add up exactly, but it
won't.)

So when you update the storage pool to set the threshold to be 99, it
will only reclaim tapes that are 1% full and 99% empty. You clearly have
none. You're actually in pretty good shape considering your threshold is
set to 60. You do not have any almost-empty tapes to reclaim.

If you're running out of scratch tapes, try setting the threshold to 50,
and then LOWERING it a point at a time to see how many you get. You
might start seeing significant reclamation activity with the threshold
set somewhere around 45. I'm constantly adjusting mine up or down a
point at a time, to achieve the level of reclamation necessary to insure
an adequate supply of scratch tapes.

One reason this is confusing, is that the default value is 50. The
default of which - emptiness or fullness? Well, at 50 it doesn't matter,
because 50% full = 50% empty after all.

Richard, you are not the first person to fall for this, and you will not
be the last. It confuses me sometimes too.

Roger Deschner      University of Illinois at Chicago     rogerd AT uic DOT edu
======== An optimist is someone who says a glass is half full. =========
== A pessimist says it's half empty. An engineering consultant says, ===
======= "Looks like you've got twice as much glass as you need." =======


>I don't necessarily want to modify the current reclamation threshold
>value on my tape storage pool (currently at 60)
>
>But I do want to do some manual reclamations to gain back some of these
>volumes at > 99% - some one off processes...   I would have thought
>issuing manual "reclaim stgpool <tapepool> threshold=99" should have
>done this??
>
>
>
>-----Original Message-----
>From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
>Jim Neal
>Sent: Tuesday, 11 November 2008 9:33 AM
>To: ADSM-L AT VM.MARIST DOT EDU
>Subject: Re: [ADSM-L] reclamation
>
>Hi Richard,
>
>    I believe the command you want to use is:
>
>upd stg <tapepool> recl=99 reclaimpr=X (where x=number of reclaim
>processes
>to start).
>
>-----Original Message-----
>From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
>Cheung, Richard
>Sent: Monday, November 10, 2008 2:56 PM
>To: ADSM-L AT VM.MARIST DOT EDU
>Subject: [ADSM-L] reclamation
>
>Hi..
>
>I have done some checks on my system on the Number of tapes to be
>reclaimed in my main tape pool, and discover the following:
>
>No of tapes awaiting reclamation at > 99% utilized = 86
>No of tapes awaiting reclamation at > 80% utilized = 51
>No of tapes awaiting reclamation at > 70% utilized = 36
>No of tapes awaiting reclamation at > 60% utilized = 23
>No of tapes awaiting reclamation at > 50% utilized = 2
>
>To facilitate this, I thought I would do some manual reclamations to
>clear the back log...
>
>However when I enter in
>
>Reclaim stgpool <tapepool> threshold=99 wait=no
>
>It tells me 'there is no data to be processed'
>
>Not sure why it would tell me that if there is supposedly 86 tapes at
>99%> pct util awaiting reclamation?
>
>Any one has any suggestions?
>
>Richard