On Thu, Jan 14, 2010 at 02:57:03PM -0500, Jeff Sturm wrote: > > -----Original Message----- > > From: linux-cluster-bounces@xxxxxxxxxx > [mailto:linux-cluster-bounces@xxxxxxxxxx] > > On Behalf Of Dirk H. Schulz > > Sent: Thursday, January 14, 2010 12:21 PM > > To: linux clustering > > Subject: Snapshotting GFS and freezing > > > > Hi folks, > > > > I found several howtos on the web stating that if you want to snapshot > a > > gfs volume (on top of clvm, of course), you have to freeze gfs (using > > gfs_tool) to make that possible. > > > > What comes in mind then is: If I have to freeze the gfs volume anyway, > > do I need a snapshot at all? Can't I copy the contents off the frozen > > gfs volume directly? > > Because the basic purpose of a snapshot is to provide files that do > not > > change during beeing copied. And I would expect a frozen gfs volume to > > provide exactly that. > > The important consideration here is: How long can you withstand the > filesystem being frozen? > > You can freeze it, copy all files (e.g. with rsync) and unfreeze, > potentially over the course of a few hours. If that's okay with your > application and users, go right ahead. > > Or you can freeze, snapshot and unfreeze, and potentially be done within > a few seconds. That's the beauty of snapshots--we do it online with > little or no user disruption. > Hmm.. so snapshots with CLVM are possible nowadays? -- Pasi -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
