I'm running iometer-2004.07.30-post.DS1. I'm doing 512
byte block random read with eight workers to eight IBM
FAStT LUNs, so one LUN per worker. 1 IO per target.
Under Windows and Redhat Enterprise Linux 3 U3, I get
1500 IO/s with eight LUNs, and proportionately fewer
with fewer LUns. Under SuSE SLES 8, I get only 300,
and I get 300 with anywhwere from 2 to 8 LUNs. With
one LUN I get 150 (same as Windows and RHEL).
Looking at the the information the adapter card gives
me, I only get two commands outstanding at a time on
SLES, where on RHEL it's 8 commands (can't see in
Windows). But the adapter card will support more than
2 IO's. But starting eight dd commands in eight shell
sessions, I can get 40 or so. This makes me think it's
IOMETER that's the problem.
SLES kernel is 2.4.21-231-smp. Hardware is IBM x345 with
two 3.0GHZ Xeons, 4G memory, Qlogic QL2342 FC card.
Any ideas what's happening?