From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?Q?Mathias_Bur=C3=A9n?= Subject: Re: mdXX: bitmap superblock UUID mismatch Date: Mon, 14 Feb 2011 16:36:29 +0000 Message-ID: References: <20110128075346.4276e2d1@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Reynald Borer Cc: NeilBrown , linux-raid@vger.kernel.org List-Id: linux-raid.ids On 14 February 2011 16:33, Reynald Borer wrot= e: > Hi, > > Nice catch for the 1 bit difference, I didn't see it. My point > regarding bitmap reconstruction was because this raid was used in a > LVM setup. the LVM partition used two distinct raid 1 disks, and I wa= s > not able to start the LVM correctly without this failing raid. > > In the end, I was able to save my LVM by simply skipping the raid 1 > and using directly one partition. The LVM tool was clever enough to > detect the MD bits and proposed me to remove them in order to mount > directly the partition, and it worked fine. Thus I was able to save m= y > data. > > Thanks for your answer though. > > Regards, > Reynald > > > On Thu, Jan 27, 2011 at 9:53 PM, NeilBrown wrote: >> On Wed, 26 Jan 2011 21:58:25 +0100 Reynald Borer >> wrote: >> >>> Hello guys, >>> >>> I have been using md raids for quite a long time now and it always >>> worked fine, until recently when I upgraded some hardware on my >>> workstation. Unfortunately the hardware I changed proved itself to = be >>> very unstable, and I encountered a lot of hard lockups of the syste= m >>> while running. Those lockups recently made one of my raid 1 array >>> fails with the infamous error message "mdXX: bitmap superblock UUID >>> mismatch". >>> >>> Here is what I have found in the kernel logs when I try to activate >>> the given raid group: >>> ----------------- >>> md/raid1:md126: active with 2 out of 2 mirrors >>> md126: bitmap superblock UUID mismatch >>> md126: bitmap file superblock: >>> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0magic: 6d746962 >>> =C2=A0 =C2=A0 =C2=A0 =C2=A0version: 4 >>> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 uuid: 37102258.af9c1930.b8397fb8= =2Eeba356af >> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0= =C2=A0 =C2=A0 =C2=A0 ^ this is an 'a' >> >>> =C2=A0 =C2=A0 =C2=A0 =C2=A0 events: 199168 >>> events cleared: 199166 >>> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0state: 00000000 >>> =C2=A0 =C2=A0 =C2=A0chunksize: 524288 B >>> =C2=A0 daemon sleep: 5s >>> =C2=A0 =C2=A0 =C2=A0sync size: 248075584 KB >>> max write behind: 0 >>> md126: failed to create bitmap (-22) >>> ----------------- >>> >>> >>> Such error messages are displayed each time I try to run the raid >>> group. Content of /proc/mdstat is: >>> ----------------- >>> md126 : inactive sdb6[0] sda6[1] >>> =C2=A0 =C2=A0 =C2=A0 496151168 blocks >>> ----------------- >>> >>> >>> If I try to examine both disks with mdadm -E it shows some checksum >>> mismatch for both partitions: >>> ----------------- >>> root@bob # mdadm -E /dev/sda6 >>> /dev/sda6: >>> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 Magic : a92b4efc >>> =C2=A0 =C2=A0 =C2=A0 =C2=A0 Version : 0.90.03 >>> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0UUID : 37102258:bf9c1930:b= 8397fb8:eba356af >> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0= =C2=A0 =C2=A0 =C2=A0 =C2=A0 ^ this is a 'b' >> >> So you certainly do have some sick hardware!!! >> >> I suggest that you find some hardware that you can trust, >> mount one of the two devices ( (sdb6 or sda6) ignoring the raid stuf= f, >> and copy data off to the device that you trust. >> >> Then start again. >> >> NeilBrown >> >> >>> =C2=A0 Creation Time : Mon Aug =C2=A07 21:06:47 2006 >>> =C2=A0 =C2=A0 =C2=A0Raid Level : raid1 >>> =C2=A0 Used Dev Size : 248075584 (236.58 GiB 254.03 GB) >>> =C2=A0 =C2=A0 =C2=A0Array Size : 248075584 (236.58 GiB 254.03 GB) >>> =C2=A0 =C2=A0Raid Devices : 2 >>> =C2=A0 Total Devices : 2 >>> Preferred Minor : 6 >>> >>> =C2=A0 =C2=A0 Update Time : Wed Jan 12 00:12:44 2011 >>> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 State : clean >>> =C2=A0Active Devices : 2 >>> Working Devices : 2 >>> =C2=A0Failed Devices : 0 >>> =C2=A0 Spare Devices : 0 >>> =C2=A0 =C2=A0 =C2=A0 =C2=A0Checksum : e4883f8e - expected e4883e8e >>> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0Events : 199168 >>> >>> >>> =C2=A0 =C2=A0 =C2=A0 Number =C2=A0 Major =C2=A0 Minor =C2=A0 RaidDe= vice State >>> this =C2=A0 =C2=A0 1 =C2=A0 =C2=A0 =C2=A0 8 =C2=A0 =C2=A0 =C2=A0 38= =C2=A0 =C2=A0 =C2=A0 =C2=A01 =C2=A0 =C2=A0 =C2=A0active sync >>> >>> =C2=A0 =C2=A00 =C2=A0 =C2=A0 0 =C2=A0 =C2=A0 =C2=A0 8 =C2=A0 =C2=A0= =C2=A0 70 =C2=A0 =C2=A0 =C2=A0 =C2=A00 =C2=A0 =C2=A0 =C2=A0active sync >>> =C2=A0 =C2=A01 =C2=A0 =C2=A0 1 =C2=A0 =C2=A0 =C2=A0 8 =C2=A0 =C2=A0= =C2=A0 38 =C2=A0 =C2=A0 =C2=A0 =C2=A01 =C2=A0 =C2=A0 =C2=A0active sync >>> root@bob # mdadm -E /dev/sdb6 >>> /dev/sdb6: >>> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 Magic : a92b4efc >>> =C2=A0 =C2=A0 =C2=A0 =C2=A0 Version : 0.90.03 >>> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0UUID : 37102258:bf9c1930:b= 8397fb8:eba356af >>> =C2=A0 Creation Time : Mon Aug =C2=A07 21:06:47 2006 >>> =C2=A0 =C2=A0 =C2=A0Raid Level : raid1 >>> =C2=A0 Used Dev Size : 248075584 (236.58 GiB 254.03 GB) >>> =C2=A0 =C2=A0 =C2=A0Array Size : 248075584 (236.58 GiB 254.03 GB) >>> =C2=A0 =C2=A0Raid Devices : 2 >>> =C2=A0 Total Devices : 2 >>> Preferred Minor : 6 >>> >>> =C2=A0 =C2=A0 Update Time : Wed Jan 12 00:12:44 2011 >>> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 State : clean >>> =C2=A0Active Devices : 2 >>> Working Devices : 2 >>> =C2=A0Failed Devices : 0 >>> =C2=A0 Spare Devices : 0 >>> =C2=A0 =C2=A0 =C2=A0 =C2=A0Checksum : e4883fac - expected e4883eac >>> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0Events : 199168 >>> >>> >>> =C2=A0 =C2=A0 =C2=A0 Number =C2=A0 Major =C2=A0 Minor =C2=A0 RaidDe= vice State >>> this =C2=A0 =C2=A0 0 =C2=A0 =C2=A0 =C2=A0 8 =C2=A0 =C2=A0 =C2=A0 70= =C2=A0 =C2=A0 =C2=A0 =C2=A00 =C2=A0 =C2=A0 =C2=A0active sync >>> >>> =C2=A0 =C2=A00 =C2=A0 =C2=A0 0 =C2=A0 =C2=A0 =C2=A0 8 =C2=A0 =C2=A0= =C2=A0 70 =C2=A0 =C2=A0 =C2=A0 =C2=A00 =C2=A0 =C2=A0 =C2=A0active sync >>> =C2=A0 =C2=A01 =C2=A0 =C2=A0 1 =C2=A0 =C2=A0 =C2=A0 8 =C2=A0 =C2=A0= =C2=A0 38 =C2=A0 =C2=A0 =C2=A0 =C2=A01 =C2=A0 =C2=A0 =C2=A0active sync >>> ----------------- >>> >>> >>> Any idea how I could try to save my raid group? >>> >>> Thanks in advance for your help. >>> >>> Best Regards, >>> Reynald >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-rai= d" in >>> the body of a message to majordomo@vger.kernel.org >>> More majordomo info at =C2=A0http://vger.kernel.org/majordomo-info.= html >> >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid"= in > the body of a message to majordomo@vger.kernel.org > More majordomo info at =C2=A0http://vger.kernel.org/majordomo-info.ht= ml > Wow, that's cool. I suppose RAID1 is simple enough for this to be possible, though. Still, cool. :-) // M -- 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