[Lustre-discuss] tunefs.lustre --print fails on mounted mdt/ost with mmp

[Andreas Dilger]

On 2010-07-14, at 13:29, Nate Pearlstein wrote:
> Just checking to be sure this isn't a known bug or problem.  I couldn't
> find a bz for this, but it would appear that tunefs.lustre --print fails
> on a lustre mdt or ost device if mounted with mmp.
> 
> Is this expected behavior?

Not really expected...  It is reading the "mountdata" file via debugfs, so that should be safe even on a mounted filesystem, but it doesn't work with MMP:

# debugfs -c -R stats /dev/vgbackup/lvtest 
debugfs 1.41.10.sun2 (24-Feb-2010)
/dev/vgbackup/lvtest: MMP: device currently active while opening filesystem
stats: Filesystem not open

This is already fixed in our next release of e2fsprogs, however, thanks to a patch Jim Garlick @ LLNL.  It is the first hunk of the patch at:

https://bugzilla.lustre.org/attachment.cgi?id=30441

> mds1-gps:~ # tunefs.lustre --print /dev/mapper/mdt1
> checking for existing Lustre data: not found
> 
> tunefs.lustre FATAL: Device /dev/mapper/mdt1 has not been formatted with
> mkfs.lustre

This error message should probably be fixed also.


Cheers, Andreas
--
Andreas Dilger
Lustre Technical Lead
Oracle Corporation Canada Inc.