From mboxrd@z Thu Jan 1 00:00:00 1970 From: "kyle" Subject: Re: change strip_cache_size freeze the whole raid Date: Mon, 22 Jan 2007 21:09:58 +0800 Message-ID: <005501c73e33$7d9046d0$28df0f3d@kylecea1512a3f> References: <001801c73e14$c3177170$28df0f3d@kylecea1512a3f> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: Justin Piszcz Cc: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-raid.ids > > 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