From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Davidsen Subject: Re: linux disk access when idle Date: Sun, 23 Aug 2009 14:23:14 -0400 Message-ID: <4A918912.2090602@tmr.com> References: <20090820163522.GA29215@sewage> <4A8D99D9.2090806@sauce.co.nz> <20090821165935.GA18915@sewage> <4A8ED2FC.2070700@redhat.com> <20090822210443.GA12033@sewage> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090822210443.GA12033@sewage> Sender: linux-raid-owner@vger.kernel.org To: Matt Garman Cc: Ric Wheeler , linux-raid List-Id: linux-raid.ids Matt Garman wrote: > On Fri, Aug 21, 2009 at 01:01:48PM -0400, Ric Wheeler wrote: > >> On 08/21/2009 12:59 PM, Matt Garman wrote: >> >>>>> So what I'm trying to figure out is, what is causing the disk >>>>> access? It could be any one of: >>>>> >>>>> - Kernel >>>>> - RAID subsystem (i.e. md) >>>>> - XFS filesystem >>>>> - NFS >>>>> - Samba >>>>> - ??? >>>>> >>>>> >>>> Are you running smartd? It polls the drives every 30minutes. >>>> >>> >>> >> I think that you can use blktrace to see who is issuing the IO's >> that spin up your drives.... >> > > For five hours today, I ran blktrace on md1 as well as the drives > that make up md1 (sd[a-d]). I also enabled block dump via > > echo 1 > /proc/sys/vm/block_dump > > Nothing. Neither block_dump nor blktrace recorded anything on md1 > or sd[abcd]. I caught one instance where the heads parked (I both > heard them park as well as saw the power meter show the 10 watt > drop). They only stayed parked for about five minutes. Yet neither > blktrace nor block_dump caught anything. > > I'm going to try lm-profiler now (from the laptop-mode-tools > package), but I have low expectations. > > I'm beginning to think that it's not even direct access to the > drives that cause the heads to unpark, e.g. perhaps even activity on > my system drive (a compact flash card connected to the PATA port) > prevents the data drives from parking their heads. > Are you doing regular self test? I'm not sure if non-io connections would show using those tools, I just haven't tried them at that level. -- bill davidsen CTO TMR Associates, Inc "Now we have another quarterback besides Kurt Warner telling us during postgame interviews that he owes every great thing that happens to him on a football field to his faith in Jesus. I knew there had to be a reason why the Almighty included a mute button on my remote." -- Arthur Troyer on Tim Tebow (Sports Illustrated)