I/O blocked to clustered mirror after "dm-log-clustered: Userspace cluster log server not found" and "clogd[XXXXX]: Failed to recv message from kernel" in RHEL 5

Issue

• I/O to a cluster mirrored logical volume blocks after we see repeated time outs, followed by "Userspace cluster log server not found." and "Failed to recv message from kernel"

Nov 29 05:40:18 node1 kernel: device-mapper: dm-log-clustered: [VmUKhcE4] Request timed out: [DM_CLOG_GET_SYNC_COUNT/42516260] - retrying
Nov 29 05:40:18 node1 kernel: device-mapper: dm-log-clustered: [aVgPDEwC] Request timed out: [DM_CLOG_STATUS_TABLE/42516261] - retrying
Nov 29 05:40:18 node1 kernel: device-mapper: dm-log-clustered: Unable to send cluster log request [DM_CLOG_STATUS_TABLE] to server: -3
Nov 29 05:40:18 node1 kernel: device-mapper: dm-log-clustered:  Userspace cluster log server not found.                
Nov 29 05:40:18 node1 clogd[31940]: Failed to recv message from kernel                                                 
Nov 29 05:40:19 node1 kernel: device-mapper: dm-log-clustered: [VGEcXSZi] Request timed out: [DM_CLOG_IN_SYNC/42516262] - retrying
Nov 29 05:40:19 node1 kernel: device-mapper: dm-log-clustered: Unable to send cluster log request [DM_CLOG_IN_SYNC] to server: -3
Nov 29 05:40:19 node1 kernel: device-mapper: dm-log-clustered:  Userspace cluster log server not found.
Nov 29 05:40:20 node1 kernel: device-mapper: dm-log-clustered: [3JEDH8Ef] Request timed out: [DM_CLOG_MARK_REGION/42516263] - retrying
Nov 29 05:40:20 node1 kernel: device-mapper: dm-log-clustered: Unable to send cluster log request [DM_CLOG_MARK_REGION] to server: -3
Nov 29 05:40:20 node1 kernel: device-mapper: dm-log-clustered:  Userspace cluster log server not found.
Nov 29 05:40:20 node1 kernel: device-mapper: dm-log-clustered: Attempting to contact cluster log server...