[DRBD-user] DRBD and LVM Snapshot with 2 nodes configuration

Andreas Semt as at computer-leipzig.de
Thu Apr 8 00:15:54 CEST 2004

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.


Greg Freemyer wrote:

> I have not been following this thread very closely, but I think one of
> the major issues is that the LVM VFS-lock patch does not work if drbd is
> layered above lvm.
> 
> If this is the only issue, then maybe xfs_freeze can be used as a work
> around.  (It can be used in the absense of the vfs-lock patch.)
> 
> With a kernel lacking the vfs-lock patch, the following does work on a
> single node setup:
> 
> xfs_freeze -f /dev/...   // Cause XFS to prepare for a snapshot
> create snapshot          
> xfs_freeze -u /dev/...   // Allow XFS to continue handling i/o

Can you verify this, i.e. production use experiences? That could be a 
possible way to go, maybe. Wonder what Lars would say ...
> 
> I don't know if any of the other filesystems over a userspace took to
> invoke freeze/unfreeze.

I don't know, but i think that's a unique feature of XFS (under Linux).
> 
> HTH
> Greg

-- 
Best regards,
Andreas Semt



More information about the drbd-user mailing list