ADSM-L

Re: tape handling

1998-09-11 06:46:21
Subject: Re: tape handling
From: Chris Roelofs <Chris.J.Roelofs AT MAIL.ING DOT NL>
Date: Fri, 11 Sep 1998 11:46:21 +0100
     Hi Fred,

     It is important to understand that tape volumes, being sequential
     access media, have the following life-cycle:
     empty/scratch -> filling -> full -> empty/scratch -> filling etc etc

     So a 60% used tape can only be filled if it has the status filling.
     If it is 60% used and has status full, you must wait for it to become
     empty/scratch or reclaim it (which is basically the same) before you
     can use it again.

     ADSM will always fill up tapes with status filling to end-of-tape
     unless:
     - A filling tape has access mode read-only or unavailable
     - Collocation is in effect

     Do some mathematics: how many clients are there, how "big" are your
     clients, what is tape-capacity, how are your policy settings?

     Chris


______________________________ Reply Separator _________________________________
Subject: tape handling
Author:  "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU> at inet-1
Date:    9/11/98 9:55 AM


Hello all,
I would like some information regarding tape-handling of ADSM. We
started out a couple of month ago with approximately 200 tapes available
for storage pool and copy storage pool. Two Month ago we noticed we were
getting short of tapes, so we added another 30, which in a month time
also filled up, so last week we added another 30. Of these, in a week
time already 18 are used up.
We have a lot of tapes presently that have only 60% data on them, so
doing space reclaimation should give me some tapes back, but I have the
impression it is grabbing for scratch tapes rather than filling up tapes
that haven't reached their max-limit yet.
Does anyone experience the same thing???
Does anyone have a solution for this ???

Your help much appreciated

Fred de Klein
Work: 01234 333453
Email: fred.deklein AT capgemini.co DOT uk
            kleinf AT compuserve DOT com
            fred_de_klein AT yahoo DOT com
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