[Lustre-discuss] OST targets not mountable after disabling/enabling MMP

[Edward Walter]

Hi Ken,

Thanks for the tip. 

This gives me an MMP error though:
[root at oss-0-25 log]# tune2fs -E clear-mmp /dev/sdd
tune2fs 1.40.11.sun1 (17-June-2008)
tune2fs: MMP: appears fsck currently being run on the filesystem while 
trying to open /dev/sdd
Couldn't find valid filesystem superblock.

At the risk of being obvious; we're not running any kind of fsck 
operation on this volume.

Also, I can still mount this volume read-only using ldiskfs as the 
filesystem type (so I'm suspicious of the filesystem superblock message).

Thanks.

-Ed

Ken Hornstein wrote:
>> We recently experienced a power failure (and subsequent UPS failure) 
>> which caused our Lustre filesystem to shutdown hard.  We were able to 
>> bring it back online but started seeing errors where the OSTs were being 
>> remounted as read-only.  We observed that all of the read-only OSTs were 
>> reporting an I/O error on the same block (the MMP block) and generating 
>> the following message:
>> [...]
>>     
>
> I had a similar issue once, but the issue was tha the MMP block was
> corrupted.  What finally fixed it was running tune2fs -E clear-mmp.
> Maybe that might solve the problem?
>
> --Ken
>
>