On Tuesday, Jan 27, 2004, at 06:45 Australia/Sydney, Bill Boyer wrote:

p630 server running AIX 5.2 ML2
TSM 5.2.2.0
2109-S16 fibre switches

When running dsmfmt on the volumes on Shark disk, the system runs at
very
high wait cpu %. at times it will jump over 90% and the system will
become
unresponsive for several seconds. When the dsmfmt completes, topas will
still show 5-8mb/sec on the Shark paths for almost another minute.
Nothing
is running.

JFS or JFS2? Do you have minperm, maxperm, maxclient and/or
strict_maxperm
tuned? What was numperm and numclient when the system started responding
again?

My recommendation is to either use raw devices, or if you don't like
that idea,
mount the given filesytems with the dio mount option set.

Cheers,
--
Paul Ripke
Unix/OpenVMS/TSM/DBA
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