We have a NW 6.5 SP5 server with 3 NSS pools. Two of them are fine, but
one suffers from really bad performance. Where you can get 8,000k/sec +
throughput to volumes in the other two pools, you only get 900-1,000k/sec
with this pool. Its 196gb in size, with 109gb used.

It was on internal disks, but is now on a SAN. It was moved to the SAN by
setting up a software mirror 1, with a segment on the internal disks and
a segment on the SAN. We then broke the mirror, leaving just the segment
on the SAN. Interestingly the mirror ran at a very fast speed, doing the
mirror in mere minutes. I/O performance to clients remains slow however.

Anyone seen anything like this before ?