[Lustre-discuss] The client profile could not be read from the MGS

[Andreas Dilger]

On 2010-01-05, at 10:57, Wojciech Turek wrote:
> On my MDS node I ran this command:
> debugfs -c -R 'ls -l CONFIGS' /dev/drbd_mds03_vg/mgs_lv
> 303121  100644 (1)      0      0       0  4-Jan-2010 11:39 work2- 
> client
>
> work2-client file is zero size and all the OST and MDT files for work2
> file system are missing.
>
> Is there a way to recover this files without stopping work2 file  
> system?
>
> If I umount all work2 OSTs and MDT and then run writeconf on them and
> mount them back, would this recreate this missing files?

I suspect yes, though I'm not really the expert in the config code.

Could you please file a bug with details.  It doesn't make sense to  
delete both configs if only rewriting one of them.  It would also be  
useful for such cases to create a backup of the config and leave it on  
the MGS before deleting it.

> Also can do above without umounting clients (let them wait until
> lustre targets come back) and would this kill any jobs running one
> them?


It shouldn't, but I'm not totally sure what they will do with the new  
configuration itself.  You will likely have to remount the clients at
some point before you make any changes to the configuration in the  
future (e.g. adding an OST or setting tunables) as the currently- 
mounted clients will likely not detect these due to the new  
configration that was created.

Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.