I know this thread is a few days old, but I wanted to comment on this issue
because I don't think any of the responses so far have got it quite right,
and I know from experience as an instructor that this is a very important
but most often misunderstood concept.
You should always think of volume management as two distinct steps: 1)
telling ADSM/TSM what is happening with the volumes (update vol/update
volhist), and 2) physically managing the automated library inventory
(checkin/checkout).
If you are planning to take tapes offsite to a vault, then the important
step is to update the access mode of those volumes to "OFFSITE". This
tells TSM that it can still so some data processing like Reclamation and
Move Data commands, but it will NEVER request a mount of the actual volume
(it uses the primary copy instead). Note that only copy pool volumes can be
set to "OFFSITE" - this is because TSM always expects to have its primary
pool volumes available (ie:mountable). The checkout operation for the
offsite copypool volumes is just a necessary extra step to get the tapes
out of the library inventory (you wouldn't need to do this if you used a
manual library). The implied moral to this story is that you should
normally NEVER checkout primary pool volumes from the library!
"But what if my library becomes full and I need to free up some slots?",
you may ask. This is why the "MOVE MEDIA" command was invented back around
release 3.1.2. It gives us the ability to have a combination
automatic/manual library. We can "move" tapes outside of the library to a
nearby "location", but the tapes are still considered as mountable. The
distinction is whether they have the media state of "MOUNABLEINLIB" or
"MOUNTABLENOTINLIB", and this tells TSM whether to ask the robot for to
mount the volume or to issue a manual mount request. We still use our good
old "Checkin Libvol" command to update the library inventory and tell TSM
that the tape is back in the robot (since that is ultamitely how the tape
gets mounted). Both primary and copy pool volumes can be "Moved" with Move
Media.
One added "feature" that you need to be aware of is that TSM will
automatically toggle the volume's access mode from ReadOnly to ReadWrite
and back again as it is Moved in and out of the library. This is to allow
any read operations to proceed (eg: restore) and cause a manual mount
request, but write operations will not attempt to access the volume. You
can override this default behaviour with options to Move Media.
I hope that helps!
At 11:15 AM 11/8/00 +0100, you wrote:
>I use MOVE MEDIA for this operation both ways, out and in the library.
>With CHECKOUT you have to provide the volume labels of the tapes you want
>to remove from the library, while with "move media" you can select by
>stgpool. I am not sure if the "checkout" changes the access to offsite but
>"Move media" creates a file with the volume label of the tapes that
>processes, and you can afterwards run a command to perform an update of the
>volumes with access=offsite.
>The only problem is that, what the command creates is a macro and can only
>be scheduled by a cron job,( my system is UNIX.)
>The macro can not be scheduled by TSM, not included in a script. It has to
>run from the command line.
>Regards
>Maria
>
>----- Original Message -----
>From: Reiner Sauer <ReinerSauer AT VINZENZ DOT DE>
>To: <ADSM-L AT VM.MARIST DOT EDU>
>Sent: Wednesday, November 08, 2000 8:26 AM
>Subject: Antw: "Move media" vs. checkout
>
>
>I've learned that to get the tape out and set in the db to offsite, is to
>use the command checkout and the tape get offsite. Now the tape is not
>availiable fpr the library. To get the tape in you should use the commands
>checkin and update volume.
>
>>>> djk AT UMICH DOT EDU 7.11.2000 22:14:11 >>>
>I'm looking at moving our copypool tapes offsite. We are not running
>DRM. I've been reading the archive of this list and it seems some people
>use the adsm checkout command and others the Move media command to remove
>the tapes from the library for offsite storage. I've read up on both and
>it seems the move media command is the right one for removing the tape from
>the library and a checkin command to bring it back in. Does anyone have
>any comments on the checkout versus "move media" command that might help
>explain their use? Am I on the right track thinking the "move media"
>command should be used?
>
>
Scott McCambly
AIX/NetView/ADSM Specialist - Unopsys Inc. Ottawa, Ontario, Canada
(613)799-9269
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