Messages in this thread | | | Date | Thu, 25 Sep 2003 12:25:17 +0200 | From | Jens Axboe <> | Subject | Re: Complete I/O starvation with 3ware raid on 2.6 |
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On Thu, Sep 25 2003, Aaron Lehmann wrote: > On Thu, Sep 25, 2003 at 07:13:32PM +1000, Nick Piggin wrote: > > But the load average will be 11 because there are processes stuck in the > > kernel somewhere in D state. Have a look for them. They might be things > > like pdflush, kswapd, scsi_*, etc. > > They're pdflush and kjournald. I don't have sysrq support compiled in > at the moment. > > I've noticed the problem does not occur when the raid can absorb data > faster than the other drive can throw data at it. My naive mind is > pretty sure that this is just an issue of way too much being queued > for writing. If someone could tell me how to control this parameter, > I'd definately give it a try [tomorrow]. All I've found on my own is > #define TW_Q_LENGTH 256 in 3w-xxxx.h and am not sure if this is the > right thing to change or safe to change.
That is the right define, try setting it to something low. 8, or maybe even 4. Don't go below 3, though.
-- Jens Axboe
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