From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: raid10 array tend to two degraded raid10 array Date: Mon, 23 Jul 2012 09:11:05 +1000 Message-ID: <20120723091105.5cb8dcf0@notabene.brown> References: <50092079.a287440a.5002.ffff88ef@mx.google.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/7OGRG.RCA0t2dLKZmTx8TH2"; protocol="application/pgp-signature" Return-path: In-Reply-To: <50092079.a287440a.5002.ffff88ef@mx.google.com> Sender: linux-raid-owner@vger.kernel.org To: vincent Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids --Sig_/7OGRG.RCA0t2dLKZmTx8TH2 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable On Fri, 20 Jul 2012 17:10:14 +0800 "vincent" wro= te: > Hi, everyone: > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0I am Vincent, I am writing to you to ask a = question about of > mdadm. > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0I created a raid10 array with 4 160G disks = used the command: mdadm > -Cv /dev/md0 -l10 -n4 /dev/sd[abcd], > =A0=A0=A0=A0=A0=A0=A0=A0=A0 The version of my mdadm is 3.2.2, and the ver= sion of my kernel=A0is > 2.6.38 > =A0=A0=A0=A0=A0=A0=A0=A0=A0 when the raid10 is in resyncing, I used the f= ollowing command to > make file system for it: mkfs.ext3 /dev/md0 > =A0=A0=A0=A0=A0=A0=A0=A0=A0 every was OK. The array continued to resync, = but when the=A0process > of resyncing is 3.4%, there were a lot of > =A0=A0=A0=A0=A0=A0=A0=A0=A0 IO error of "sda" and "sdc". There were bad b= locks in sda and sdc. > =A0=A0=A0=A0=A0=A0=A0=A0=A0 Then I used "cat /proc/mdstat" to see the sta= tus of /dev/md0: > =A0 > =A0=A0=A0=A0=A0=A0=A0=A0=A0 Personalities=A0:=A0[raid10]=A0=A0=A0=A0=A0=A0 > =A0=A0=A0=A0=A0=A0=A0=A0=A0 md0=A0:=A0active=A0raid10=A0sdb[1]=A0sdd[3] > =A0=A0=A0=A0=A0=A0=A0=A0=A0 310343680=A0blocks=A0super=A01.2=A0512K=A0chu= nks=A02=A0near-copies=A0[4/2]=A0[_U_U] > =A0 > =A0=A0=A0=A0=A0=A0=A0=A0=A0 unused=A0devices:=A0 > =A0=A0=A0=A0=A0=A0=A0=A0=20 > =A0=A0=A0=A0=A0=A0=A0=A0=A0 /dev/sdc and /dev/sda had lost.=20 > =A0=A0=A0=A0=A0=A0=A0=A0=A0 Then=A0I reboot the system, but when i used "= cat /proc/mdstat" to > see the status of /dev/md0: > =A0 > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0Personalities=A0:=A0[raid10]=A0 > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0md126=A0:=A0active=A0raid10=A0sda[0]=A0sdc[= 2] > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0310343680=A0blocks=A0super=A01.2=A0512K=A0c= hunks=A02=A0near-copies=A0[4/2]=A0[U_U_] > =A0=A0=A0=A0=A0=A0 > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0md0=A0:=A0active=A0raid10=A0sdb[1]=A0sdd[3] > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0310343680=A0blocks=A0super=A01.2=A0512K=A0c= hunks=A02=A0near-copies=A0[4/2]=A0[_U_U] > =A0=A0=A0=A0=A0=A0 > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0unused=A0devices:=A0 > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=20 > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0there had a array which name was md126, and= consisted by /dev/sdc > /dev/sda. > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0I used "mdadm --assemble --scan" to assembl= e the=A0md devices. the > output=A0of the command is: > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=20 > =A0=A0=A0=A0=A0=A0=A0=A0=A0 dm:=A0/dev/md/0=A0exists=A0-=A0ignoring > =A0=A0=A0=A0=A0=A0=A0=A0=A0 md:=A0md0=A0stopped. > =A0=A0=A0=A0=A0=A0=A0=A0=A0 mdadm:=A0ignoring=A0/dev/sda=A0as=A0it=A0repo= rts=A0/dev/sdd=A0as=A0failed > =A0=A0=A0=A0=A0=A0=A0=A0=A0 mdadm:=A0ignoring=A0/dev/sdc=A0as=A0it=A0repo= rts=A0/dev/sdd=A0as=A0failed > =A0=A0=A0=A0=A0=A0=A0=A0=A0 md:=A0bind > =A0=A0=A0=A0=A0=A0=A0=A0=A0 md:=A0bind > =A0=A0=A0=A0=A0=A0=A0=A0=A0 md/raid10:md0:=A0active=A0with=A02=A0out=A0of= =A04=A0devices > =A0=A0=A0=A0=A0=A0=A0=A0=A0 md0:=A0detected=A0capacity=A0change=A0from=A0= 0=A0to=A0317791928320 > =A0=A0=A0=A0=A0=A0=A0=A0=A0 mdadm:=A0/dev/md0=A0has=A0been=A0started=A0wi= th=A02=A0drives=A0(out=A0of=A04). > =A0=A0=A0=A0=A0=A0=A0=A0=A0 md0:=A0unknown=A0partition=A0table > =A0=A0=A0=A0=A0=A0=A0=A0=A0 mdadm:=A0/dev/md/0=A0exists=A0-=A0ignoring > =A0=A0=A0=A0=A0=A0=A0=A0=A0 md:=A0md126=A0stopped. > =A0=A0=A0=A0=A0=A0=A0=A0=A0 md:=A0bind > =A0=A0=A0=A0=A0=A0=A0=A0=A0 md:=A0bind > =A0=A0=A0=A0=A0=A0=A0=A0=A0 md/raid10:md126:=A0active=A0with=A02=A0out=A0= of=A04=A0devices > =A0=A0=A0=A0=A0=A0=A0=A0=A0 md126:=A0detected=A0capacity=A0change=A0from= =A00=A0to=A0317791928320 > =A0=A0=A0=A0=A0=A0=A0=A0=A0 mdadm:=A0/dev/md126=A0has=A0been=A0started=A0= with=A02=A0drives=A0(out=A0of=A04). > =A0=A0=A0=A0=A0=A0=A0=A0=A0 md126:=A0unknown=A0partition=A0table > =A0 > =A0=A0=A0=A0=A0=A0=A0=A0=A0 And then=A0I used "mdadm -E /dev/sda", "mdadm= -E /dev/sdb", "mdadm > -E=A0/dev/sdc", "mdadm -E /dev/sdc" ,=20 > =A0=A0=A0=A0=A0=A0=A0=A0=A0 "mdadm -D /dev/md0" and "mdadm -D /dev/md127"= to=A0 check the > details info of sda, sdb, sdc and sdd.=20 > =A0=A0=A0=A0=A0=A0=A0=A0=A0 I found=A0the property of "Array UUID" of all= of these devices(sda, > sdb, sdc, sdd)were the same. But the=20 > =A0=A0=A0=A0=A0=A0=A0=A0=A0 property of "Events" and "Update Time" of "sd= a" and=A0"sdc" were the > same(21, =A0Fri Jul 6 11:02:09 2012),=A0=20 > =A0=A0=A0=A0=A0=A0=A0=A0=A0 the property of "Events" and "Update Time" of= "sdb" and "sdd" were > the same(35,=A0 Fri Jul 6 11:06:21 2012). > =A0 > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0Although the "Update Time" and "events" pro= perty of "sda" and > "sdc" were not equal to "sdb" and=A0"sdd",=20 > =A0=A0=A0=A0=A0=A0=A0=A0=A0 they had the same=A0"Array UUID". why=A0this = array tend=A0to=A0two > degraded arrays those had the same uuid?=A0 > =A0=A0=A0=A0=A0=A0=A0=A0=A0 As the two arrays had the same uuid, it is di= fficult to > distinguish and=A0use them. I think it is unreasonable, > =A0=A0=A0=A0=A0=A0=A0=A0=A0 could you help me ? >=20 Yes, this is a known problem. Hopefully it will be fixed in the next relea= se of mdadm. =20 For now, just remove the faulty devices, or at least remove the metadata fr= om them with mdadm --zero-superblock /dev/sd[ac] NeilBrown --Sig_/7OGRG.RCA0t2dLKZmTx8TH2 Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) iQIVAwUBUAyIiTnsnt1WYoG5AQK20RAAiW8khgTWK8d4+lJHbP2MDE8/aebcWVnV RfVybg0ELArd9BuIgKeHklvSMA31zSHRXd4nGKQpemlsZic+fX81/YT1VVjOn9xX t3vucdfYy0mtOrhiaiTh+wNWp/qZYNzOcwyCA2pnzF16axPWjhPsH/+cU3Vgc5Eg dKithTDvi1/1fC0E1U12wHGunyOdSR6ngcWMJjiDszuqIRarLLWSAJEGq0CNhDhQ 1Grnxfa1FCPMxT5F3Ml1XDXkF9gtLQw9Bvqj/Bn3ffbJiRuwznmxv+EMR7J4nPRt UIvtHJJyrdKVy+Zs8ZkcGrebo/oZrpVCCEZs7kv0v5jeYZ41UyzWwbphPM62REgo dn5Z1ZO98mhSs9vA12sdRCtpd/+tBb4ViSIXfPk9P5vIHMvAHiyBMUKjfjowiQ4j lY6lFnNfMWlTyJOekOuYMtaeg6Mr5EAvmfHWmf78J9IaJstreGveybLFZc05rktQ WhmViRZx07vhnxL/YAuFwAf9c1C0jEo7JTjx/IqfM/IXGfVrrVefhD30BVmrovjo bPe8WDgonuKLL1aHCair13nv0YvzAjVvSkDzmeTBBucUoosX/vEWGyQpLuLcBg5z QVEsSCTRnuYBz9w9gGAGE5Y7yUYZ8TFj+6gh8ri5AMaeBjGc2sU+zayIdpBsLD30 g4fTKD0RwvA= =jObp -----END PGP SIGNATURE----- --Sig_/7OGRG.RCA0t2dLKZmTx8TH2--