From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Don Dupuis" Subject: Re: Md corruption using RAID10 on linux-2.6.21 Date: Wed, 16 May 2007 21:58:59 -0500 Message-ID: <632b79000705161958m67a192bav73ab3dafc08825d0@mail.gmail.com> References: <632b79000705161138h359f71egdf4ad5d483731dbe@mail.gmail.com> <17995.46536.195175.894763@notabene.brown> <632b79000705161957j5443e3b9h1d6da8593395f736@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <632b79000705161957j5443e3b9h1d6da8593395f736@mail.gmail.com> Content-Disposition: inline Sender: linux-raid-owner@vger.kernel.org To: Neil Brown Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 5/16/07, Don Dupuis wrote: > On 5/16/07, Neil Brown wrote: > > On Wednesday May 16, dondster@gmail.com wrote: > > ... > > > > > > The problem arises when I do a drive removal such as sda and then I > > > remove power from the system. Most of the time I will have a corrupted > > > partition on the md device. Other corruption will be my root partition > > > which is an ext3 filesystem. I seem to have a better chance of booting > > > a least 1 time with no errors with bitmap turned on, but If I repeat > > > the process, I will have corruption as well. Also with bitmap turned > > > on, adding the new drive into the md device will take way to too long. > > > I only get about 3MB per second on the resync. With bitmap turned off, > > > I will get between 10MB to 15MB resync rate. Has anyone else seen this > > > behavior, or is this situation is no tested very often? I would think > > > that I shouldn't get corruption with this raid setup and jornaling of > > > my filesytems? Any help would be appreciated. > > > > > > The resync rate should be the same whether you have a bitmap or not, > > so that observation is very strange. Can you double check, and report > > the contents of "/proc/mdstat" in the two situations. > > > > You say you have corruption on your root filesystem. Presumably that > > is not on the raid? Maybe the drive doesn't get a chance to flush > > it's cache when you power-off. Do you get the same corruption if you > > simulate a crash without turning off the power. e.g. > > echo b > /proc/sysrq-trigger > > > > Do you get the same corruption in the raid10 if you turn it off > > *without* removing a drive first? > > > > NeilBrown > > > Powering off with all drives will not have corruption. When I have a > drive missing and the md device does a full resync, I will get the > corruption. Usually the md partition table is corrupt or gone. and > with the first drive gone it happens more frequently. If the partition > table is not corrupt, then the rootfilesystem or one of the other > filesystems on the md device will be corrupted. Yes my root filesystem > is on the raid device. I will update with the bitmap resync rate stuff > later. > > Don > Forgot to tell you that I have the drive write cache disabled on all my drives. Don