On Wed, 2004-01-28 at 02:28, R Dicaire wrote: > On Tue, 2004-01-27 at 21:53, Little, Chris wrote: > > is the filesystem you are snapshotting still mounted when you execute the > > snapshot? They need to be offline before the snapshot takes place. > > Yes, they are still mounted when I take a snapshot, I must have missed that > in the docs, that in itself poses a problem as I then cant umount the volumes > without killing services. I'd understood the snapshotting process as being > able to snapshot a live filesystem, and then mount the snapshot to perform > backups from it instead of the live filesystem. Whats the purpose of the > --size arg to lvcreate when taking a snapshot, I thought it was a buffer > to hold data that'd normally be written to disk but cant when the > snapshot exists? I'm confused. > I snapshot live mounted volumes every day. (LVM 1.x, kernel 2.4.21) It works. I use xfs. For LVM snapshot to work with mounted filesystems you either have to have the vfs-lock patch applied or invoke a filesystem freeze from user space prior to creating the snapshot. With xfs, I use the xfs_freeze command from userspace. Then on the xfs mount, I have to use the "-o ro,nouuid" flag to mount the snapshot because the master volume and the snapshot have the same uuid. Greg -- Greg Freemyer _______________________________________________ linux-lvm mailing list linux-lvm@sistina.com http://lists.sistina.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
