From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kyle Liddell Subject: Re: linux disk access when idle Date: Sat, 22 Aug 2009 01:02:44 -0400 Message-ID: <1250917364.2889.29.camel@athlon> References: <20090820163522.GA29215@sewage> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090820163522.GA29215@sewage> Sender: linux-raid-owner@vger.kernel.org To: Matt Garman Cc: linux-raid List-Id: linux-raid.ids On Thu, 2009-08-20 at 11:35 -0500, 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 > - ??? For one, syslogd. It's probably worthwhile to look up information for laptop power saving. In particular, laptop-mode in the kernel, and laptop-mode-tools: http://samwel.tk/laptop_mode I use this on my laptop, and I don't think I ever have a "surprise" disk spinup. The whole laptop-mode-tools setup is probably much more than you want, but it's a good place to start. The FAQ there also mentions how to get syslog to stop syncing to disk. You may also find 'lm-profiler' useful - this will tell you the which process is causing disk accesses. Finally, for general power saving, 'powertop' tracks the power state information for your CPU, and will list the processes that are causing your CPU to come out of any sleep/idle states.