On Wed, Nov 30, 2005 at 08:01:20AM +0100, Wallace Wadge wrote: > Hi, > > I've got a hardware raid in place. I'd like to add snapshots via lvm to it > but unfortunately the underlying filesystem is ext3 which cannot be resized > downwards; therefore I would like to add another disk. > > Now for the problem: > > I would like to add a secondary (physical) disk to the mix and use it for > snapshots only. However I do not want the lvm to stay writing to that disk > for normal data since this seconday disk would not be part of my hardware > raid. In other words, I wouldn't care if the snapshot drive failed because I > would just replace it. > > Is this at all possible? Hi Wallace, yes, it is. pvcreate the physical disk and vegextend your VG by it. When creating snapshots, add the path to that PV (say /dev/sdc) to the lvcreate command line: lvcreate -LSnapshotSize -nSnapshotName /dev/YourVG/YourLV /dev/sdc You need to make sure though, that spave for LVs you want to be resilient, gets allocated on your HW RAID, rather than to the single drive PV. There's 2 ways to achive that: o add the path to your HW-RAID to all your lvcreate/lvextend commands (but the ones to create snapshots) o if your snapshots are short-term (which is typical), vgreduce the VG by the single drive PV until you need to create (a) snapshot(s) again; of course that solution falls short with respect to creating/extending LVs *while* the PV is a member of your VG > > Thanks. > Wallace > _______________________________________________ > linux-lvm mailing list > linux-lvm@redhat.com > https://www.redhat.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ -- Regards, Heinz -- The LVM Guy -- *** Software bugs are stupid. Nevertheless it needs not so stupid people to solve them *** =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Heinz Mauelshagen Red Hat GmbH Consulting Development Engineer Am Sonnenhang 11 Cluster and Storage Development 56242 Marienrachdorf Germany Mauelshagen@RedHat.com +49 2626 141200 FAX 924446 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
