RHEL3: iowait and idle output swapped(?) in top

[Mike Burger]

I've recently inherited a small set of RHEL installations, which were run
through P2V and are now running as VMWare guests.

The users were complaining that one of them, running as an oracle server,
appeared to be running slowly.

Of course, my first instinct was to run top, which showed a pretty high
iowait number (around 134% for a 2 CPU instance).

As it turned out that we were running a deduplication on the storage that
housed the VM, our VM admin had the storage team stop the dedupe...our
thought was that the iowait might be in the storage area, and that turning
off the dedupe might speed things up.

The opposite effect was shown in the iowait number...it actually went up,
and has hovered around 170-190% since stopping the dedupe, while the
number in the idle column hovers between 0 and 10%.

vCenter and our monitoring tools (CA's eHealth) show the opposite...they
show the CPU's idle state between 80 and 95, during the period since
stopping the dedupe.

My question...has anyone else seen a situation where top, running on a
multi-cpu config, in (or not) a VM, might have the iowait and and idle
numbers reversed in the top output (procps 2.0.17)?

Thank you.


-- 
Mike Burger
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