From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jody McIntyre Subject: Re: [RFC patch 1/1] Track raid5/6 statistics. Date: Thu, 27 Nov 2008 08:52:48 -0500 Message-ID: <20081127135248.GD29919@clouds> References: <20081126190452.775333692@sun.com> <20081126190854.813151413@sun.com> <20081127114748.GE14570@boogie.lpds.sztaki.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7BIT Return-path: In-reply-to: <20081127114748.GE14570@boogie.lpds.sztaki.hu> Content-disposition: inline Sender: linux-raid-owner@vger.kernel.org To: Gabor Gombas Cc: linux-raid@vger.kernel.org, neilb@suse.de List-Id: linux-raid.ids Hi Gabor, On Thu, Nov 27, 2008 at 12:47:48PM +0100, Gabor Gombas wrote: > Are these values useful for mere mortals trying to create a RAID array > best suited for a specific workload, or are these only useful for people > hacking on the RAID code? I believe the average administrator could understand what most (if not all) of the statistics mean, but doing something about it might require a developer or at least someone with a bit of RAID experience. In our use, we get customers to report the values to us then make tuning suggestions (more likely) or provide a patch. > If the former, then I'd suggest to use sysfs (something like > /sys/block//md/statistics, similar to > /sys/class/net//statistics). If the latter, then debugfs would be > better. I was thinking about your first suggestion but note that there is also /proc/diskstats as well as /sys/block//stat. The advantage of having everything in one file is that you only have to open one file when gathering statistics on many arrays, and /proc/mdstat already exists as a precedent. I could add individual array statistics files as well if useful. I'm also going to investigate tracepoints as suggested by Dan, so all this is subject to change :) Cheers, Jody > > Gabor > > -- > --------------------------------------------------------- > MTA SZTAKI Computer and Automation Research Institute > Hungarian Academy of Sciences > ---------------------------------------------------------