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

[Ken Hornstein]

>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