logs shows messages "kernel: drbd nfsinfo sv81426: conn( Connected -> NetworkFailure ) peer( Primary -> Unknown )" on server

Issue

• /var/log/messages lists the following messages:

kernel: drbd nfsinfo sv81426: PingAck did not arrive in time.
kernel: drbd nfsinfo sv81426: conn( Connected -> NetworkFailure ) peer( Primary -> Unknown )
kernel: drbd nfsinfo/0 drbd1: disk( UpToDate -> Consistent )
kernel: drbd nfsinfo/0 drbd1 sv81426: pdsk( UpToDate -> DUnknown ) repl( Established -> Off )
kernel: drbd nfsinfo sv81426: ack_receiver terminated
kernel: drbd nfsinfo sv81426: Terminating ack_recv thread
kernel: drbd nfsinfo: Preparing cluster-wide state change 2368493027 (0->-1 0/0)
kernel: drbd nfsinfo: Committing cluster-wide state change 2368493027 (0ms)
kernel: drbd nfsinfo/0 drbd1: disk( Consistent -> UpToDate )
kernel: drbd nfsinfo sv81426: Connection closed