I have seen the disk caching/reclaim issue, but I've only noticed it
with LTO drives. 3590, 3570, DLT, etc., all seem to work fine with disk
caching turned on. And frankly, LTO drives are speedy enough that
turning off disk caching hasn't even been an issue from a performance
standpoint.

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Mark Stapleton
Sent: Thursday, September 12, 2002 12:08 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: Is reclamation working?

From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU]On Behalf Of
Gill, Geoffrey L.
> I have noticed I have about 145 volumes that are less than 25%
utilized,
> most of these are in the offsite pool. Reclamation runs on the offsite
pool
> daily, sometimes, like this morning, I find it is still running.
Reclamation
> kicks off at 5PM with reclaim=50. I'm not understanding why these
aren't
> being reclaimed quicker.

Is your disk pool cached? If it isn't, you can ignore the rest of this
post.

If it is, that's the problem. Reclamation will use disk-located files in
preference to tape-located files, and the MOVEBATCHSIZE server parameter
gets ignored for disk-located files. (Why? Who knows?) The result?
Reclamation processes will move files from disk to tape one file at a
time.
*Slow*.

The fix? Tivoli says a code fix would be "massive". The workaround? Turn
off
caching in your disk pools. (I know--it's like curing a hangnail by
cutting
your finger off.)

--
Mark Stapleton (stapleton AT berbee DOT com)
Certified TSM consultant
Certified AIX system engineer
MCSE