rr_min_io 1 dev_loss_tmo 600 fast_io_fail_tmo 5 } Before itso-sles12-powerha-n-1 :~ # multipath -ll | grep dm mpathd (360050768028c8449c00000000000024e) dm-8 IBM,2145 mpathc (360050768028c8449c00000000000024d) dm-7 IBM,2145 mpathb (360050768028c8449c00000000000024c) dm-6 IBM,2145 mpatha (360050768028c8449c00000000000024b) dm-5 IBM,2145 ROOTVG (360050768028c8449c000000000000212) dm-0 IBM,2145 itso-sles12-powerha-n-1 :~ # service multipathd restart itso-sles12-powerha-n-1 :~ # service multipathd reload itso-sles12-powerha-n-1 :~ # multipath -ll | grep dm ROOTVG  (360050768028c8449c000000000000212) dm-0 IBM,2145 DATA3  (360050768028c8449c00000000000024d) dm-7 IBM,2145 HEARTBEAT  (360050768028c8449c00000000000024e) dm-8 IBM,2145 DATA2  (360050768028c8449c00000000000024c) dm-6 IBM,2145 DATA1  (360050768028c8449c00000000000024b) dm-5 IBM,2145 itso-sles12-powerha-n-2 :~ # service multipathd restart itso-sles12-powerha-n-2 :~ # service multipathd reload itso-sles12-powerha-n-2 :~ # multipath -ll | grep dm ROOTVG  (360050768028c8449c000000000000244) dm-0 IBM,2145 DATA3  (360050768028c8449c00000000000024d) dm-6 IBM,2145 HEARTBEAT  (360050768028c8449c00000000000024e) dm-8 IBM,2145 DATA2  (360050768028c8449c00000000000024c) dm-7 IBM,2145 DATA1  (360050768028c8449c00000000000024b) dm-5 IBM,2145 itso-sles12-powerha-n-1 :~ # lsrsrc IBM.Disk DeviceInfo NodeNameList Resource Persistent Attributes for IBM.Disk resource 1: DeviceInfo = "UUID=360050768028c8449c00000000000024d" NodeNameList = {"Unknown_Node_Name","itso-sles12-powerha-n-1"} resource 2: DeviceInfo = "UUID=360050768028c8449c00000000000024e" NodeNameList = {"Unknown_Node_Name","itso-sles12-powerha-n-1"} resource 3: DeviceInfo = "UUID=360050768028c8449c00000000000024b" NodeNameList = {"Unknown_Node_Name","itso-sles12-powerha-n-1"} resource 4: DeviceInfo = "UUID=360050768028c8449c00000000000024c" NodeNameList = {"Unknown_Node_Name","itso-sles12-powerha-n-1"} resource 5: DeviceInfo = "UUID=360050768028c8449c00000000000024c" 21.Now the multipath services are restarted, as shown in Example 11-35. 22.We always suggest that you avoid allowing a partitioned or divided brain cluster to add a  heartbeat disk to the cluster. We create one with the label  HEARTBEAT,  the UUID of the  disk is validated and can be found with the  lsrsrc IBM.Disk DeviceInfo NodeNameList command. Also, you can find the UUID with the  multipath -ll  command, as shown in  Example 11-36 and in Example 11-37 on page 449. Example 11-36 Validate the UUID of the heartbeat disk Example 11-35 Multipath before and after 448  IBM PowerHA SystemMirror V7.2.3 for IBM AIX and V7.2.2 for Linux