rr_min_io 1 dev_loss_tmo 600 fast_io_fail_tmo 5 } 

21.Now the multipath services are restarted, as shown in Example 11-35. 

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 

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. 

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" 

