ADSM-L

Re: neat trick to clear cache pointers...

2004-01-27 15:12:39
Subject: Re: neat trick to clear cache pointers...
From: David Longo <David.Longo AT HEALTH-FIRST DOT ORG>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Tue, 27 Jan 2004 15:11:42 -0500
I did somethign like thsi a couple of weeks ago with a TSM 4.2.3.4
server.  I was just reconfiguring my disk pools. not truing to do
anything else.

It seems that a move data on a cached disk pool volume does not "move" 
the data to other volumes, it deletes/empties the cached volume.




David B. Longo
System Administrator
Health First, Inc.
3300 Fiske Blvd.
Rockledge, FL 32955-4305
PH      321.434.5536
Pager  321.634.8230
Fax:    321.434.5509
david.longo AT health-first DOT org


>>> cookde AT US.IBM DOT COM 01/27/04 02:23PM >>>
This might be old news but I just noticed a real neat event while clearing
a cached disk pool on an AIX TSM 5.1.7.0 server...

So I have a disk pool with some 19 volumes for about 550 GB of storage.

Two migrations were running but I fired off an additional six move data's
to occupy all the tape drives.
I had set all the volumes to read only via a "upd vol * acc=reado
wherestg=<mydiskpool>"
Now, I still had 60% utilized but only 20% migratable and in wanting to not
just sit and twiddle my thumbs, I went to do a move data against one of the
volumes not currently being processed in hopes of clearing the cache
pointers from it.
Remember, I currently have no idea how much is cache and how much is actual
data yet to be migrated to tape...

Upon starting a plain move data back into the same storage pool, which has
all its volumes marked as read-only...
Suddenly ALL the volumes started dropping their "Pct Util" reflected in a
"q vol stg=<mydiskpool>"
Some 330 GB of cache pointers across 19 volumes was cleared in about 30
seconds by that one move data command.

I guess in actually having some real data on that volume, and in wanting to
move it to another volume within that same pool, but not being able to
allocate any space (due to all the volumes marked read-only) triggered the
~cache-master~ to start clearing cache and boy did it !

not what I expected but neat

Dwight

##############################################################
This message is for the named person's use only.  It may 
contain confidential, proprietary, or legally privileged 
information.  No confidentiality or privilege is waived or 
lost by any mistransmission.  If you receive this message 
in error, please immediately delete it and all copies of it 
from your system, destroy any hard copies of it, and notify 
the sender.  You must not, directly or indirectly, use, 
disclose, distribute, print, or copy any part of this message
if you are not the intended recipient.  Health First reserves
the right to monitor all e-mail communications through its
networks.  Any views or opinions expressed in this message
are solely those of the individual sender, except (1) where
the message states such views or opinions are on behalf of 
a particular entity;  and (2) the sender is authorized by 
the entity to give such views or opinions.
##############################################################

<Prev in Thread] Current Thread [Next in Thread>