[ClusterLabs] DRBD failover in Pacemaker

[Dmitri Maziuk]

On 2016-09-08 02:03, Digimer wrote:

> You need to solve the problem with fencing in DRBD. Leaving it off WILL
> result in a split-brain eventually, full stop. With working fencing, you
> will NOT get a split-brain, full stop.

"Split brain is a situation where, due to temporary failure of all 
network links between cluster nodes, and possibly due to intervention by 
a cluster management software or human error, both nodes switched to the 
primary role while disconnected."
  -- DRBD Users Guide 8.4 # 2.9 Split brain notification.

About the only practical problem with *DRBD* split brain under pacemaker 
is that pacemaker won't let you run "drbdadm secondary && drbdadm 
connect --discard-my-data" as easy as busted ancient code did.

Dima