ADSM-L

Re: Volume consolidation.

1999-04-30 22:14:08
Subject: Re: Volume consolidation.
From: Russell Street <russells AT AUCKLAND.AC DOT NZ>
Date: Sat, 1 May 1999 14:14:08 +1200
> In ADSM, is it possible to perform volume consolidation?
> If it is, where can I get information on how to do this?

It is quite simple:

use dsmfmt to create new, large files to hold the database and log data

in the ADSM admin program, define new database volumes and log volumes
Do not extend the database/log to use the new space.

then delete the old database and log volumes one at a time.  When
you delete the volumes, ADSM will move the pages on the volume are
deleting to the other volumes.  You will see background processes
running doing this.

once the background process completes, VERIFY THE VOLUME is no
longer used by ADSM (qu logv/dbv) .  Then you can delete the underlying file.

If at the end of the exercise the total database or log space is
bigger than when you started, use "extend db/log" to let ADSM use the
additional space.



All this can be done with the system on line and working normally.



Gotchas are

you need enough free space: if you want to consolidate two 1GB
volumes you need 2GB of free space to do that.

the way ADSM fills database volumes means it can copy data around
more than once in this procedure, e.g.,

  - you have two 1GB database volumes (db1.dsm and db2.dsm)
  - db1.dsm is 100% full, the db2.dsm 50% full (as seen by query dbv f=d)
  - You then create and define a 2GB volume to consolidate them.
  - If you ran "delete dbv db1.dsm" first, ADSM will continue to fill up
    the db2.dsm volume.
    Once that is 100% full, it will move on to your new 2GB volume.
    You then have to delete db2.dsm.  ADSM will then copy all of the
    pages that were there before you started, plus a whole lot it
    moved in from db1.dsm.
  - Deleting db2.dsm then db1.dsm will stop the double handling

database backups can not run when database deletes are occuring.  If
you have triggered database backups take steps to prevent them from
firing off.


Russell
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