High IO Wait - PowerEdge 2650 - Perc 3/Di
Jeff.Tillotson at KnowledgeStorm.com
Fri Jan 19 11:46:51 CST 2007
>On Fri, Jan 19, 2007 at 09:18:35AM -0500, Tillotson, Jeff wrote:
>> The system is hanging during or after file writes. If I do something
>> dd if=/dev/zero of=/home/jefft/file1 bs=512 count=864000 the system
>> will eventually hang and come back. Using sar, iostat, top, I can
>> watch iowait percentage climb and climb until it hangs.
>Then, when I
>> can gain access again, it drops slowly. The iowait
>percentage goes up
>> even after the dd has completed.
>Jeff, another question. Is this reproduceable every time? I
>just tried it on one of our 2650's that had had BIOS updates
>done, and while I saw some spikes in iowait activity, the
>system remained useable and the file finished writing without
Everytime. The funny thing is the IO Wait continues, and really spikes,
after the copy has completed. The system never actually crashes it just
"freezes" for a period of time.
Thanks for everyone's response. I am trying some of the suggestions
during the day. Well, except for the don't use PERC controller one :).
My arms aren't that long.
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