From mboxrd@z Thu Jan 1 00:00:00 1970 From: jahammonds prost Subject: Re: Failed Array Rebuild advice Please Date: Wed, 11 Apr 2012 19:10:47 -0700 (PDT) Message-ID: <1334196647.20850.YahooMailNeo@web125501.mail.ne1.yahoo.com> References: <1334097164.41181.YahooMailNeo@web125506.mail.ne1.yahoo.com> <20120411090219.78392784@notabene.brown> <1334117647.68845.YahooMailNeo@web125505.mail.ne1.yahoo.com> <20120411144302.35f13f3d@notabene.brown> Reply-To: jahammonds prost Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20120411144302.35f13f3d@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: NeilBrown Cc: Linux RAID List-Id: linux-raid.ids > I think it is best to recover, and then reshape later. =A0 Which is what I did. The destructive badblocks ran fine overnight, with= no errors on the drives that were failed out of the array. Interesting= ly one of the additional drives that I want to add took an additional 6= hours to run badblocks, so I need to look into that a bit. =A0 I am having a bit of an issue with the reshape tho... When I try and ad= d one of the 2 additional devices I want to add (I'm going to add them = one at a time), I get an error about the bitmap needing to be removed. =A0 =A0=A0=A0=A0=A0=A0=A0=A0mdadm --grow /dev/md0 --raid-devices=3D16 =A0=A0=A0=A0=A0=A0=A0=A0mdadm: Need to backup 93184K of critical sectio= n.. =A0=A0=A0=A0=A0=A0=A0=A0mdadm: Cannot set device shape for /dev/md0: De= vice or resource busy =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0Bitmap must be removed bef= ore shape can be changed Now, the docs (and indeed several websites when I googled) suggest that= you can have a bitmap present on a grow, and the help suggests that yo= u can even change it during a grow.. =A0=A0=A0=A0=A0=A0=A0=A0=A0If the word internal is given, then the bitm= ap is stored with the metadata on the array, and so is replicated on al= l devices.=A0 If the word none is given with --grow mode, then any bitm= ap that is present is removed. Is there an issue with the array, or just in my understanding and googl= e foo? I am running on Centos 6 (2.6.32-220.7.1.el6.x86_64) with madam (mdadm = - v3.2.2 - 17th June 2011) Thanks again. =A0 ----- Original Message ----- =46rom: NeilBrown To: jahammonds prost Cc: Linux RAID Sent: Wednesday, 11 April 2012, 0:43 Subject: Re: Failed Array Rebuild advice Please On Tue, 10 Apr 2012 21:14:07 -0700 (PDT) jahammonds prost wrote: > One other question as the badblocks progresses. > =A0 > >=A0 It will then recovery both devices in parallel. >=20 > How many additional devices can be done at the same time? I presume t= hat I am going to have to=A0replace the 2 failed devices before I try a= nd grow the array by adding 3 additional drives? I so, how many=A0addit= ional drives can be rebuilt concurrently with a grow? Could I add 5 dev= ices and not see too much of a performance hit? Or would it be more sen= sible to add them one at a time? >=20 I think it is best to recover, and then reshape later.=A0 I cannot prom= ise that doing them both at once will work .... it might but I have a feeling th= at there might be problems. Adding three additional drives at once should work well enough in terms= of performance. However I would only do it if I were very very confident of the drives. If you hit bad blocks you start losing drives, and if you have 3 drives= that you haven't used before, the chance of losing them all during the resha= pe - while still small - becomes a little too high for comfort. But if you have run heavy bad-blocks tests on them all and they appear = to work, then adding 3 drives at once should be fine. NeilBrown -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html