Thank you for the response. I need a couple of clarifications. On Mon, Feb 13, 2012 at 9:35 PM, Brassow Jonathan <jbras...@redhat.com> wrote: > > On Feb 10, 2012, at 11:46 PM, Manish Kathuria wrote: > >> On a two node (active-passive) cluster with external storage on RHEL >> 6.1, we need to use Snapshots for taking backup of the logical volumes >> on the storage. As per the documentation, snapshots are not supported >> on clustered logical volumes (using CLVM). Since each of the logical >> volumes on the external storage are going to be exclusively mounted >> (and used) by a single node at any point of time, we can therefore use >> HA-LVM instead of CLVM. However, for configuring HA-LVM also, there >> are two suggested methods >> (https://access.redhat.com/kb/docs/DOC-3068): >> >> - first one is the simpler one, using the CLVM variant while the other >> one is the original method using volume_list and VG tags. >> >> I have a few queries related to both. >> >> Do snapshots work if we configure HA-LVM using CLVM and run the clvmd >> daemon ? > > Yes (recently). Whether you are using HA-LVM or CLVM, if the logical volume > is exclusive, you can snapshot it. >
As mentioned in the documentation, we have to make a logical volume unavailable after creating using the "lvchange -an" command. Do we need to use any similar commands or extra options while creating the snapshots ? The snapshots are going to be created and mounted on the active node using scripts run through crond. >> In case of the original HA-LVM configuration method, can we leave the >> volume_list in /etc/lvm/lvm.conf blank since we are not going to have >> any shared VGs or LVs except for those which are going to be shared >> using HA-LVM. > > You can't leave the volume_list blank. Doing so would mean that your > computer could not find your local drives the next time it boots up - forcing > you to boot into an old kernel to bring the machine up. You must at least > put the local VGs in the volume list. We are planning to use LVM only on the shared storage and not on the internal devices on the nodes. The /boot, / and swap partitions would be simple partitions of a hardware RAID device formatted with ext4 and there would not be any local VGs. That was the reason I asked this question. > brassow > -- Manish -- Linux-cluster mailing list Linux-cluster@redhat.com https://www.redhat.com/mailman/listinfo/linux-cluster
