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* mdXX: bitmap superblock UUID mismatch
@ 2011-01-26 20:58 Reynald Borer
  2011-01-27 20:53 ` NeilBrown
  0 siblings, 1 reply; 4+ messages in thread
From: Reynald Borer @ 2011-01-26 20:58 UTC (permalink / raw)
  To: linux-raid

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 system
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:
         magic: 6d746962
       version: 4
          uuid: 37102258.af9c1930.b8397fb8.eba356af
        events: 199168
events cleared: 199166
         state: 00000000
     chunksize: 524288 B
  daemon sleep: 5s
     sync 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]
      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:
          Magic : a92b4efc
        Version : 0.90.03
           UUID : 37102258:bf9c1930:b8397fb8:eba356af
  Creation Time : Mon Aug  7 21:06:47 2006
     Raid Level : raid1
  Used Dev Size : 248075584 (236.58 GiB 254.03 GB)
     Array Size : 248075584 (236.58 GiB 254.03 GB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 6

    Update Time : Wed Jan 12 00:12:44 2011
          State : clean
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0
       Checksum : e4883f8e - expected e4883e8e
         Events : 199168


      Number   Major   Minor   RaidDevice State
this     1       8       38        1      active sync

   0     0       8       70        0      active sync
   1     1       8       38        1      active sync
root@bob # mdadm -E /dev/sdb6
/dev/sdb6:
          Magic : a92b4efc
        Version : 0.90.03
           UUID : 37102258:bf9c1930:b8397fb8:eba356af
  Creation Time : Mon Aug  7 21:06:47 2006
     Raid Level : raid1
  Used Dev Size : 248075584 (236.58 GiB 254.03 GB)
     Array Size : 248075584 (236.58 GiB 254.03 GB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 6

    Update Time : Wed Jan 12 00:12:44 2011
          State : clean
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0
       Checksum : e4883fac - expected e4883eac
         Events : 199168


      Number   Major   Minor   RaidDevice State
this     0       8       70        0      active sync

   0     0       8       70        0      active sync
   1     1       8       38        1      active sync
-----------------


Any idea how I could try to save my raid group?

Thanks in advance for your help.

Best Regards,
Reynald

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: mdXX: bitmap superblock UUID mismatch
  2011-01-26 20:58 mdXX: bitmap superblock UUID mismatch Reynald Borer
@ 2011-01-27 20:53 ` NeilBrown
  2011-02-14 16:33   ` Reynald Borer
  0 siblings, 1 reply; 4+ messages in thread
From: NeilBrown @ 2011-01-27 20:53 UTC (permalink / raw)
  To: Reynald Borer; +Cc: linux-raid

On Wed, 26 Jan 2011 21:58:25 +0100 Reynald Borer <reynald.borer@gmail.com>
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 system
> 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:
>          magic: 6d746962
>        version: 4
>           uuid: 37102258.af9c1930.b8397fb8.eba356af
                           ^ this is an 'a'

>         events: 199168
> events cleared: 199166
>          state: 00000000
>      chunksize: 524288 B
>   daemon sleep: 5s
>      sync 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]
>       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:
>           Magic : a92b4efc
>         Version : 0.90.03
>            UUID : 37102258:bf9c1930:b8397fb8:eba356af
                             ^ 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 stuff,
and copy data off to the device that you trust.

Then start again.

NeilBrown


>   Creation Time : Mon Aug  7 21:06:47 2006
>      Raid Level : raid1
>   Used Dev Size : 248075584 (236.58 GiB 254.03 GB)
>      Array Size : 248075584 (236.58 GiB 254.03 GB)
>    Raid Devices : 2
>   Total Devices : 2
> Preferred Minor : 6
> 
>     Update Time : Wed Jan 12 00:12:44 2011
>           State : clean
>  Active Devices : 2
> Working Devices : 2
>  Failed Devices : 0
>   Spare Devices : 0
>        Checksum : e4883f8e - expected e4883e8e
>          Events : 199168
> 
> 
>       Number   Major   Minor   RaidDevice State
> this     1       8       38        1      active sync
> 
>    0     0       8       70        0      active sync
>    1     1       8       38        1      active sync
> root@bob # mdadm -E /dev/sdb6
> /dev/sdb6:
>           Magic : a92b4efc
>         Version : 0.90.03
>            UUID : 37102258:bf9c1930:b8397fb8:eba356af
>   Creation Time : Mon Aug  7 21:06:47 2006
>      Raid Level : raid1
>   Used Dev Size : 248075584 (236.58 GiB 254.03 GB)
>      Array Size : 248075584 (236.58 GiB 254.03 GB)
>    Raid Devices : 2
>   Total Devices : 2
> Preferred Minor : 6
> 
>     Update Time : Wed Jan 12 00:12:44 2011
>           State : clean
>  Active Devices : 2
> Working Devices : 2
>  Failed Devices : 0
>   Spare Devices : 0
>        Checksum : e4883fac - expected e4883eac
>          Events : 199168
> 
> 
>       Number   Major   Minor   RaidDevice State
> this     0       8       70        0      active sync
> 
>    0     0       8       70        0      active sync
>    1     1       8       38        1      active 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-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: mdXX: bitmap superblock UUID mismatch
  2011-01-27 20:53 ` NeilBrown
@ 2011-02-14 16:33   ` Reynald Borer
  2011-02-14 16:36     ` Mathias Burén
  0 siblings, 1 reply; 4+ messages in thread
From: Reynald Borer @ 2011-02-14 16:33 UTC (permalink / raw)
  To: NeilBrown; +Cc: linux-raid

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 was
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 my
data.

Thanks for your answer though.

Regards,
Reynald


On Thu, Jan 27, 2011 at 9:53 PM, NeilBrown <neilb@suse.de> wrote:
> On Wed, 26 Jan 2011 21:58:25 +0100 Reynald Borer <reynald.borer@gmail.com>
> 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 system
>> 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:
>>          magic: 6d746962
>>        version: 4
>>           uuid: 37102258.af9c1930.b8397fb8.eba356af
>                           ^ this is an 'a'
>
>>         events: 199168
>> events cleared: 199166
>>          state: 00000000
>>      chunksize: 524288 B
>>   daemon sleep: 5s
>>      sync 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]
>>       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:
>>           Magic : a92b4efc
>>         Version : 0.90.03
>>            UUID : 37102258:bf9c1930:b8397fb8:eba356af
>                             ^ 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 stuff,
> and copy data off to the device that you trust.
>
> Then start again.
>
> NeilBrown
>
>
>>   Creation Time : Mon Aug  7 21:06:47 2006
>>      Raid Level : raid1
>>   Used Dev Size : 248075584 (236.58 GiB 254.03 GB)
>>      Array Size : 248075584 (236.58 GiB 254.03 GB)
>>    Raid Devices : 2
>>   Total Devices : 2
>> Preferred Minor : 6
>>
>>     Update Time : Wed Jan 12 00:12:44 2011
>>           State : clean
>>  Active Devices : 2
>> Working Devices : 2
>>  Failed Devices : 0
>>   Spare Devices : 0
>>        Checksum : e4883f8e - expected e4883e8e
>>          Events : 199168
>>
>>
>>       Number   Major   Minor   RaidDevice State
>> this     1       8       38        1      active sync
>>
>>    0     0       8       70        0      active sync
>>    1     1       8       38        1      active sync
>> root@bob # mdadm -E /dev/sdb6
>> /dev/sdb6:
>>           Magic : a92b4efc
>>         Version : 0.90.03
>>            UUID : 37102258:bf9c1930:b8397fb8:eba356af
>>   Creation Time : Mon Aug  7 21:06:47 2006
>>      Raid Level : raid1
>>   Used Dev Size : 248075584 (236.58 GiB 254.03 GB)
>>      Array Size : 248075584 (236.58 GiB 254.03 GB)
>>    Raid Devices : 2
>>   Total Devices : 2
>> Preferred Minor : 6
>>
>>     Update Time : Wed Jan 12 00:12:44 2011
>>           State : clean
>>  Active Devices : 2
>> Working Devices : 2
>>  Failed Devices : 0
>>   Spare Devices : 0
>>        Checksum : e4883fac - expected e4883eac
>>          Events : 199168
>>
>>
>>       Number   Major   Minor   RaidDevice State
>> this     0       8       70        0      active sync
>>
>>    0     0       8       70        0      active sync
>>    1     1       8       38        1      active 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-raid" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://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  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: mdXX: bitmap superblock UUID mismatch
  2011-02-14 16:33   ` Reynald Borer
@ 2011-02-14 16:36     ` Mathias Burén
  0 siblings, 0 replies; 4+ messages in thread
From: Mathias Burén @ 2011-02-14 16:36 UTC (permalink / raw)
  To: Reynald Borer; +Cc: NeilBrown, linux-raid

On 14 February 2011 16:33, Reynald Borer <reynald.borer@gmail.com> wrote:
> 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 was
> 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 my
> data.
>
> Thanks for your answer though.
>
> Regards,
> Reynald
>
>
> On Thu, Jan 27, 2011 at 9:53 PM, NeilBrown <neilb@suse.de> wrote:
>> On Wed, 26 Jan 2011 21:58:25 +0100 Reynald Borer <reynald.borer@gmail.com>
>> 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 system
>>> 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:
>>>          magic: 6d746962
>>>        version: 4
>>>           uuid: 37102258.af9c1930.b8397fb8.eba356af
>>                           ^ this is an 'a'
>>
>>>         events: 199168
>>> events cleared: 199166
>>>          state: 00000000
>>>      chunksize: 524288 B
>>>   daemon sleep: 5s
>>>      sync 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]
>>>       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:
>>>           Magic : a92b4efc
>>>         Version : 0.90.03
>>>            UUID : 37102258:bf9c1930:b8397fb8:eba356af
>>                             ^ 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 stuff,
>> and copy data off to the device that you trust.
>>
>> Then start again.
>>
>> NeilBrown
>>
>>
>>>   Creation Time : Mon Aug  7 21:06:47 2006
>>>      Raid Level : raid1
>>>   Used Dev Size : 248075584 (236.58 GiB 254.03 GB)
>>>      Array Size : 248075584 (236.58 GiB 254.03 GB)
>>>    Raid Devices : 2
>>>   Total Devices : 2
>>> Preferred Minor : 6
>>>
>>>     Update Time : Wed Jan 12 00:12:44 2011
>>>           State : clean
>>>  Active Devices : 2
>>> Working Devices : 2
>>>  Failed Devices : 0
>>>   Spare Devices : 0
>>>        Checksum : e4883f8e - expected e4883e8e
>>>          Events : 199168
>>>
>>>
>>>       Number   Major   Minor   RaidDevice State
>>> this     1       8       38        1      active sync
>>>
>>>    0     0       8       70        0      active sync
>>>    1     1       8       38        1      active sync
>>> root@bob # mdadm -E /dev/sdb6
>>> /dev/sdb6:
>>>           Magic : a92b4efc
>>>         Version : 0.90.03
>>>            UUID : 37102258:bf9c1930:b8397fb8:eba356af
>>>   Creation Time : Mon Aug  7 21:06:47 2006
>>>      Raid Level : raid1
>>>   Used Dev Size : 248075584 (236.58 GiB 254.03 GB)
>>>      Array Size : 248075584 (236.58 GiB 254.03 GB)
>>>    Raid Devices : 2
>>>   Total Devices : 2
>>> Preferred Minor : 6
>>>
>>>     Update Time : Wed Jan 12 00:12:44 2011
>>>           State : clean
>>>  Active Devices : 2
>>> Working Devices : 2
>>>  Failed Devices : 0
>>>   Spare Devices : 0
>>>        Checksum : e4883fac - expected e4883eac
>>>          Events : 199168
>>>
>>>
>>>       Number   Major   Minor   RaidDevice State
>>> this     0       8       70        0      active sync
>>>
>>>    0     0       8       70        0      active sync
>>>    1     1       8       38        1      active 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-raid" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at  http://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  http://vger.kernel.org/majordomo-info.html
>

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" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2011-02-14 16:36 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-01-26 20:58 mdXX: bitmap superblock UUID mismatch Reynald Borer
2011-01-27 20:53 ` NeilBrown
2011-02-14 16:33   ` Reynald Borer
2011-02-14 16:36     ` Mathias Burén

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