Re: change strip_cache_size freeze the whole raid

From: kyle
Date: Mon Jan 22 2007 - 09:42:38 EST



On Mon, 22 Jan 2007, kyle wrote:

Hi,

Yesterday I tried to increase the value of strip_cache_size to see if I can
get better performance or not. I increase the value from 2048 to something
like 16384. After I did that, the raid5 freeze. Any proccess read / write to
it stucked at D state. I tried to change it back to 2048, read
strip_cache_active, cat /proc/mdstat, mdadm stop, etc. All didn't return back.
I even cannot shutdown the machine. Finally I need to press the reset button
in order to get back my control.

Yes, I noticed this bug too, if you change it too many times or change it
at the 'wrong' time, it hangs up when you echo numbr >
/proc/stripe_cache_size.

Basically don't run it more than once and don't run it at the 'wrong' time
and it works. Not sure where the bug lies, but yeah I've seen that on 3
different machines!

Justin.



I just change it once, then it freeze. It's hard to get the 'right time'

Actually I tried it several times before. As I remember there was once it freezed for around 1 or 2 minutes , then back to normal operation. This is the first time it completely freezed and I waited after around 10 minutes it still didn't wake up.

Kyle

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