From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ivan Lezhnjov IV Subject: Re: Running check and e2fsck simultaneously Date: Mon, 11 Nov 2013 01:11:59 +0200 Message-ID: <73CFFCD7-1519-49A4-8817-5C1C1A85186F@gmail.com> References: <527FCBAF.4070208@hardwarefreak.com> <58CD4AD8-0A1E-42E8-984D-F4727EE2B8F0@gmail.com> <527FDBC1.4000009@hardwarefreak.com> <20131111073428.583b83b2@notabene.brown> Mime-Version: 1.0 (Mac OS X Mail 6.2 \(1499\)) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8BIT Return-path: In-Reply-To: <20131111073428.583b83b2@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: NeilBrown Cc: stan@hardwarefreak.com, "linux-raid@vger.kernel.org" List-Id: linux-raid.ids On Nov 10, 2013, at 10:34 PM, NeilBrown wrote: > On Sun, 10 Nov 2013 13:17:21 -0600 Stan Hoeppner > wrote: > >> Also, I see little/no value in running a scheduled mdadm check on a >> RAID1 array. Any problems with RAID1 will be due to one of the disks >> beginning to fail in some mode, usually requiring sector relocation. > > I think scrubbing has value on any RAID with redundancy. > The firmware can only relocate a sector if it reads it when it is marginal > but not yet completely lost. If a sector is not read for a long time and > during that time the media degraded beyond recovery the firmware cannot do > anything. But RAID1 can - it can get it from the other device. > > NeilBrown I think this is very relevant in my case. I typically offload a bulk of data to these drives, frequently using only some parts of it. So, it sounds like having check/scrubbing run on a schedule (how often is a reasonable frequency? every two weeks perhaps?) is a good idea after all. Ivan