[Lustre-discuss] e2scan for backup

[Andreas Dilger]

On Mar 13, 2008  12:59 +0100, Jakob Goldbach wrote:
> On Wed, 2008-03-12 at 23:12 +0100, Brian J. Murrell wrote:
> > On Wed, 2008-03-12 at 14:50 -0600, Lundgren, Andrew wrote:
> > > How do you do the snapshot?
> > 
> > lvcreate -s
> 
> No need to freeze the filesystem while creating the snapshot to ensure a
> consistent filesystem on the snapshot ?

Yes, but this is handled internally by LVM and ext3 when the snapshot
is created.

> (xfs has a xfs_freeze function that does just this)

In fact I was just discussing this with an XFS developer and this is
a source of problems for them because if you do xfs_freeze before doing
the LVM snapshot it will deadlock.

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