From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jon Nelson" Subject: Re: AWFUL reshape speed with raid5. Date: Mon, 28 Jul 2008 15:56:27 -0500 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Disposition: inline Sender: linux-raid-owner@vger.kernel.org To: David Lethe Cc: Justin Piszcz , LinuxRaid List-Id: linux-raid.ids On Mon, Jul 28, 2008 at 2:59 PM, David Lethe wrote: >>-----Original Message----- >>From: linux-raid-owner@vger.kernel.org > [mailto:linux-raid-owner@vger.kernel.org] On Behalf Of Justin Piszcz >>Sent: Monday, July 28, 2008 2:44 PM >>To: Jon Nelson >>Cc: LinuxRaid >>Subject: Re: AWFUL reshape speed with raid5. >> >>There once was a bug in an earlier kernel, in which the min_speed is > what >>the rebuild ran at if you had a specific chunk size, have you tried to >>echo 30000 > to min_speed? Does it increase it to 30mb/s for the > rebuild? As I said in my original post, I'm running 2.6.25.11 > You are incorrectly working from the premise that vmstat is measures > disk activity. It does not. Vmstat has no idea how many actual bytes > get sent to, or received from disk drives. Fair enough. > Why not do a real test and hook up a pair of SAS, SCSI, or FC disks, ... Cost. -- Jon