heavy i/o wait and system hangs dual opteron and pci raid cards

[Jeff Johnson]

Greetings,

    Has anyone observed heavy i/o waits, sometimes leading to 
unrecoverable hangs, when using pci raid cards (3-Ware, Adaptec, LSI) on 
dual opteron motherboards? I am testing a dual O248 system with a 3-Ware 
9500-12 as the boot device. I have seen 3Ware and other raid cards 
(Adaptec, LSI) show heavy i/o wait but in this case since / and swap are 
on the 3Ware the i/o wait eventually cripples the system since access to 
swap and binaries are hindered.

    I have tried 'noapic pci=noapic noacpi' for boot args but it doesn't 
seem to do much. If I run iozone on the box 'iozone -a -s 1g' I can 
cripple the box. Trying to login to vc2 fails since the system cannot 
access the login binary and the process cannot read passwd, shadow, etc.

    I am running a 2.4.21-15.ELsmp kernel. I have tried more recent ones 
but haven't seen any notable improvement.

Any ideas, comments or suggestions are appreciated.

Jeff


-- 
Best Regards,

Jeff Johnson
Vice President
Engineering/Technology
Western Scientific, Inc
jeff at wsm.com
http://www.wsm.com

9445 Farnham Street - San Diego, CA 92123
Tel 800.443.6699  +001.858.565.6699
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