[Lustre-discuss] clean unmounting of OST with external journal

[Oleg Drokin]

Hello!

On Mar 6, 2011, at 8:43 PM, Samuel Aparicio wrote:
> now an attempt to re-mount the OST fails with 
> LDISKFS-fs (md14): failed to open journal device unknown-block(152,225): -6
> 
> an e2fsck fixes this external superblock 
> 
> [root at OST2 ~]# e2fsck -j /dev/etherd/e9.24p1 /dev/md14
> e2fsck 1.41.10.sun2 (24-Feb-2010)
> Superblock hint for external superblock should be 0x409802.  Fix<y>? yes

Hm, to me it sounds like after you restarted the network and reimport AoE,
then it created the device with different minor/major.
I believe that the path to the journal is stored in superblock or some such, not just the "hint" on how to find the journal.
(hint is just major:minor).
(-6 is "No such device or address", I wonder where does that come from inside of the kernel)

> 
> the subsequent OST is marked clean and can be re-mounted.
> 
> I am not sure why this is happening. The external raid partitions of relevance are all presented under the same /dev/ device when they are stopped/re-started.
> any ideas?

Did you check that device major,minor pair is the same every time?

I guess you can use journal_dev mount option to point ldiskfs at the proper journal device.

Bye,
    Oleg