ADSM-L

Re: Minor gotcha on upgrade to 5.3

2005-03-16 09:21:38
Subject: Re: Minor gotcha on upgrade to 5.3
From: Remco Post <r.post AT SARA DOT NL>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Wed, 16 Mar 2005 15:21:23 +0100
Jurjen Oskam wrote:
Hi there,

some of you might remember that I encountered a problem when upgrading
TSM from 5.2 to 5.3. The problem was that FILE-volumes reached a premature
end-of-volume, causing a 64 MiB volume to only be 1,5 % used but still
be full.

The cause of this is now known, and it's not a bug but still something
to be aware of. In TSM 5.3, the handling of FILE volumes was changed.
All writes to such a volume is now done in blocks of 256 KiB minimum,
even when the object itself is much smaller.

In my case, the storagepool only contained directories. (DIRMC option
pointing to a small DISK pool, which migrated to the affected FILE pool)
In TSM 5.2 and earlier, this wasn't a problem. In 5.3 (and presumably
later), each tiny object now takes up 256 KiB at a minumum, causing
a *huge* overhead.


and IBM sells this as WAD? Does this also affect tape storage (not likely).

The solution was to stop using FILE volumes for this pool, but only DISK
volumes.

Regards,
--
Jurjen Oskam


--
Met vriendelijke groeten,

Remco Post

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