After setting up the DM-MP multipath driver, make sure that the DM-MP configuration is set up correctly and that ALUA mode is operational.
Steps
- Type SMdevices.
If operating in the correct mode, the output displays either Active/Optimized
or Active/Non-optimized at the end of each line. The host can see the LUNs that are mapped to it.
If not operating in the correct mode, the output displays as either passive
or unowned.
- At the command prompt, type multipath -ll.
If both controllers are online, there should be exactly two path groups for each LUN, one for each controller.
If your system is running Automatic Load Balancing, the output should look as follows. Note the priority values of 50 and 10, and hwhandler='1 alua'. These indicate the correct mode for DM-MP with Automatic Load Balancing:
360080e50001b076d0000cd2451ef5e8a dm-8 NETAPP,INF-01-00
size=5.0G features='4 queue_if_no_path pg_init_retries 50 retain_attached_hw_handle' hwhandler='1 alua’ wp=rw
|-+- policy='round-robin 0' prio=50 status=enabled
| |- 8:0:2:2 sdn 8:208 active ready running
| `- 8:0:3:2 sdy 65:128 active ready running
`-+- policy='round-robin 0' prio=10 status=enabled
|- 7:0:2:2 sdc 8:32 active ready running
`- 7:0:3:2 sdaj 66:48 active ready running
If your system is not running Automatic Load Balancing, the output should look as follows. Look for priority values greater than 8 and hwhandler='1 rdac'. These indicate the correct operational mode for DM-MP without Automatic Load Balancing:
360080e50001b076d0000cd2451ef5e8a dm-8 NETAPP,INF-01-00
size=5.0G features='4 queue_if_no_path pg_init_retries 50 retain_attached_hw_handle' hwhandler='1 rdac’ wp=rw
|-+- policy='round-robin 0' prio=14 status=enabled
| |- 8:0:2:2 sdn 8:208 active ready running
| `- 8:0:3:2 sdy 65:128 active ready running
`-+- policy='round-robin 0' prio=9 status=enabled
|- 7:0:2:2 sdc 8:32 active ready running
`- 7:0:3:2 sdaj 66:48 active ready running
