This guide describes DRBD version 8.4 and above. For 8.3 please look here.
After you have created your new DRBD resource and completed your initial cluster configuration, you must enable and start the following system services on both nodes of your GFS cluster:
cman(this also starts ccsd and fenced),
clvmd.
This guide describes DRBD version 8.4 and above. For 8.3 please look here.