From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Hamrle Subject: Re: sw raid5 hungs on resync and high IO load, 2.6.32.23 Date: Wed, 27 Oct 2010 12:48:13 +0200 Message-ID: <4CC8036D.5090605@nangu.tv> References: <4CC7D635.6050000@nangu.tv> <20101027190117.5118fe0c@notabene> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7BIT Return-path: In-Reply-To: <20101027190117.5118fe0c@notabene> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 27.10.2010 10:01, Neil Brown wrote: > On Wed, 27 Oct 2010 09:35:17 +0200 > Martin Hamrle wrote: > >> Hi, >> >> I'm having this issue on several boxes with several configuration. >> One of them is a box with 8 drives attached to ARC-1160 in pass through >> mode and build sw raid5 from these drives. There is also one drive to OS. >> >> During resync or check and heavy IO load, process tscpd (tscpd is IO >> load maker) hungs, the machine is still alive but there are many blocked >> processes. >> After tscpd hungs, IO load is generated only by resync. In traceback you >> can see blocked processes (ps, htop cat) accessing tscpd cmdline in >> proc. Some tscpd threads is blocked during writing files into fs on >> raid5. Reading these files is also blocking, reading other files in >> filesystem is fast as usual. This state takes 110 minutes. After that >> all blocked processes continue their work. >> >> I am not sure what is the reason of the end of the weird state. I think >> the end was caused by starting copying kernel source into array. >> >> Note that this is first time when hung processes wake up I never wait so >> long. >> >> I think that it is related to sw raid because I do not see this issue on >> hw raid or on sw raid without resync. >> >> kern.log contains initial "INFO: task collectd:2577 blocked for more >> than 120 seconds" >> and two dumps >> echo w> /proc/sysrq-trigger >> >> log is located http://files.nangu.tv/kernel/kern.log >> Let me know if you need more info. >> > When I try to access your kern.log I get > > 403 - Forbidden Sorry about that, it is fixed now > Just include it in-line in the email. > > NeilBrown