Re: change strip_cache_size freeze the whole raid



On Mon, 22 Jan 2007, kyle wrote:


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

-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html


What kernel version are you using? It normally works the first time for
me, I put it in my startup scripts, as one of the last items. However, if
I change it a few times, it will hang and there is no way to reboot except
via SYSRQ or pressing the reboot button on the machine.

This seems to be true of 2.6.19.1 and 2.6.19.2, I did not try under
2.6.20-rc5 because I am tired of hanging my machine :)

Justin.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/