From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eyal Lebedinsky Subject: Re: mismatch_cnt again Date: Sat, 07 Nov 2009 18:49:33 +1100 Message-ID: <4AF5268D.60900@eyal.emu.id.au> References: <4AF4C247.6050303@eyal.emu.id.au> <4AF4D323.6020108@panix.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4AF4D323.6020108@panix.com> Sender: linux-raid-owner@vger.kernel.org To: linux-raid list List-Id: linux-raid.ids Berk, I am not sure that I understood your response. As I explained, I did start with a clean slate: New hardware, new system install and a zero mismatch count. After three months the weekly 'check' detected a mismatch. During this period there were no hardware errors reported on this system. smart shows no issues with the disks. You ask "Do you have any logs showing these strangenesses?" and I have none, just a non-zero count from a raid check. About cables: Does the sata protocol have checksums on the transactions? I always assumed so but never looked into it. I also ran a long memtest before commissioning the new hardware. cheers Eyal berk walker wrote: > Eyal Lebedinsky wrote: >> For years I found the mismatch_cnt rising regularly every few weeks >> and could >> never relate it to any evens. >> >> I since replaced the computer, installed fedora 11 (was very old debian) >> and only kept the array itself (ext3 on 5x1TB raid5). I had the raid >> 'repair'ed to get it to mismatch_cnt=0. >> >> I thought that I saw the last of these. I had a good run for almost three >> months, then last week I saw the first mismatch_cnt=184. It was still so >> on this weekly 'check'. >> >> I cannot see any bad event logged. >> >> Are there situations known to cause this without an actual hardware >> failure? >> I know that this came up in the past (often) but I see little recent >> discussion and wonder what the current status is. >> >> For the last 6 weeks (my uptime) the machine runs >> 2.6.30.5-43.fc11.x86_64 #1 SMP >> >> The raid holds data (no root or swap) used mostly as DVR (nothing heavy). >> smartd checks each week and so far no errors. The disks are modern 1yo >> "SAMSUNG HD103UJ". >> >> TIA >> > >I< am not quite sure what you are reporting as a problem here, sir. > "new computer".. drives ~ 1 yr old...mismatch..I know.. seems like > things just want to die .. > Do you have any logs showing these strangenesses? > > I suggest - start off with SOMETHING at zero point, then track what > changes... oh BTW did you change the drive cables? > > Best to you, > b- -- Eyal Lebedinsky (eyal@eyal.emu.id.au)