I am studying up on HA Clusters using pacemaker and corosync. The Red Hat documentation treats LVM, HA-LVM and CLVM as separate topics.
I understand the added features and benefits of CLVM over HA-LVM. What I am not sure of is what HA-LVM is compared to just regular LVM?
Is it just a mater of how you use it? If you exclude the shared volume group from the volume_list in lvm.conf on each node to prevent the local system from activating the it and then use a pacemaker resource to manage the activation and deactivation of the shared volume group does that makes it HA-LVM. Or is there actually different code that constitutes HA-LVM.
When using clvm your actually installing additional packages to provide clvmd and dlm. With HA-LVM there does not appear to be any additional packages or directives you enable to claim you want HA-LVM mode. But the way the documentation treats it and uses the terminology I am a bit confused.