[DRBD-user] DRBD 8.3 : Active resource in read only mode after a JFS bug

Fabrice LE CREURER f.lecreurer at numlog.fr
Fri Jun 19 12:56:32 CEST 2009

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Lars Ellenberg a écrit :
> On Fri, Jun 19, 2009 at 11:16:09AM +0200, Fabrice LE CREURER wrote:
>   
>> Hi,
>>
>> We used a DRBD 8.3 with three nodes manage with Heartbeat. We've got a
>> problem between first active lower device SV1 and the stacked SV3
>> device. After this problem, the drbd device was always active in SV1 but
>> only in read mode ! All third node was synchronized correctly and we
>> could used normaly DRBD device /dev/drbd1.
>> We have detected many network failure between first virtual device and
>> stacked device but without problem after resynchronizations but we have
>> the following message during production mode :
>>
>> Jun 18 15:43:45 sv1 kernel: drbd1: rw=25, want=253899392, limit=253891608
>> Jun 18 15:43:45 sv1 kernel: attempt to access beyond end of device
>>
>> Thank for your help.
>>
>> Regards
>>
>>
>>     The configuration :
>>        SV1                          -|                       
>>           lower device /dev/drbd0    |
>>           device /dev/sda9
>>        |
>>        |                               SV3
>>        |                                  stacked device /dev/drbd1
>>                                           device /dev/sda9
>>        SV2                           |
>>           lower device /dev/drbd0   -|
>>           device /dev/sda9
>>     
>
>   
>> Jun 18 15:43:45 sv1 kernel: drbd1: rw=25, want=253899432, limit=253891608
>>     
>
>   
>> Partition /dev/drbd0 :
>>     
>>> fdisk -s /dev/drbd0
>>>       
>> 126949716
>>
>> We the same disk structure for all nodes : /dev/sda9
>>     
>>> fdisk -s /dev/sda9
>>>       
>> 126953631
>>     
>
> fdisk -s reports size in kB.  the kernel messages in 512 byte sectors.
> lets bring them both to sectors:
> sda9  -> 253907262
> drbd0 -> 253899432 # this happens to be the "want=" above.
> drbd1 -> 253891608 # from the "limit=" above.
>
>
> sda9 253907262 sectors, - (size of internal meta data, aligned to 4k)
> resulting drbd0 size: 253899432. correct.
> drbd0 size - (size of internal meta data of the "upper", stacked, drbd1)
> resulting drbd1 size: 253891608. correct.
> but your  file system tries to access the sector number corresponding
> to the last sector of drbd0.
>
> conclusio: you created your file system on the (lower) drbd0,
> and when creating the meta data for the (upper) drbd1,
> you truncated your file system.
>
>   
Thank you Lars. So, what must I do ?
Should I put the meta-data external on the 3 nodes ?

Best regards

-- 
Fabrice LE CREURER
Développement / Support technique EDTI FT-MASTER
Developer engineer / Helpdesk FT-MASTER product
NUMLOG - Internet : http://www.numlog.fr
Tel : (+33) 1 30 79 16 16 - Fax: (+33) 1 30 81 92 86




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