GFS uses CLVM, the cluster-aware version of LVM, to manage block devices to be used by GFS. In order to use CLVM with DRBD, ensure that your LVM configuration
uses clustered locking. To do this, set the following
option in /etc/lvm/lvm.conf:
locking_type = 3
scans your DRBD devices to recognize DRBD-based Physical Volumes (PVs). This applies as to conventional (non-clustered) LVM; see the section called “Configuring a DRBD resource as a Physical Volume” for details.