Lustre discuss - Apr 2010 - Un-export filesystem on multi-filesystem MGS

I have a lustre filesystem that needed to be reformatted, and keep the 
same name as before. We have a single MGS for several filesystems, so 
the MGT could not be reformatted during fs creation. The MGS is still 
exporting a fs of the same name, so I cannot remount because 
registration fails. Is there a way to tell the MGS to stop exporting the 
old filesystem, and remove the old entries to allow me to use the same name?
Thanks,
Dustin

-- 
Dustin Leverman                             
HPC Systems Administrator                  
National Center for Computational Sciences
Oak Ridge National Laboratory 
e-mail: leverman at ornl.gov

On 2010-04-05, at 10:18, Dustin Leverman wrote:
> I have a lustre filesystem that needed to be reformatted, and keep the
> same name as before. We have a single MGS for several filesystems, so
> the MGT could not be reformatted during fs creation. The MGS is still
> exporting a fs of the same name, so I cannot remount because
> registration fails. Is there a way to tell the MGS to stop exporting  
> the
> old filesystem, and remove the old entries to allow me to use the  
> same name?

The easiest way to do this is to to unmount the MGS filesystem as type  
lustre, and mount it as type ldiskfs, do a backup of the filesystem,  
then delete the configuration file for the old filesystem that you  
want to re-use.  This should be in the CONFIGS/ subdirectory, IIRC.

Cheers, Andreas
--
Andreas Dilger
Principal Engineer, Lustre Group
Oracle Corporation Canada Inc.