You can use the command-line interface (CLI) to discover managed disks
(MDisks).
About this task
The system automatically discovers the back-end controller and integrates the controller to
determine the storage that is presented to the system nodes when back-end controllers are:
- Added to the Fibre Channel
- Included in the same switch zone as a system
The Small Computer System Interface (SCSI) logical units (LUs) that are presented by the
back-end controller are displayed as unmanaged MDisks. However, if the configuration of the
back-end controller is modified after this has occurred, the system might be unaware of these
configuration changes. You can request that the system rescan
the Fibre
Channel SAN to update the list of unmanaged MDisks.
Note: The automatic discovery completed
by the system does not write anything to an unmanaged MDisk. You must instruct the system to
add an MDisk to a storage pool or use an MDisk to create an image mode volume.
Discover (and then view) a list of MDisks:
Procedure
-
Issue the detectmdisk CLI command to manually scan the Fibre Channel network. The scan discovers any new MDisks that might
have been added to the system and can help rebalance MDisk access across the available
controller device ports.
Notes:
- Only issue the detectmdisk command when you are sure that all of the
disk controller ports are working and correctly configured in the controller and the SAN
zoning. Failure to do this can result in errors that are not reported.
- Although it might appear that the detectmdisk command has completed,
extra time might be required for it to run. The detectmdisk is
asynchronous and returns a prompt while the command continues to run in the background. You
can use the lsdiscoverystatus command to view the discovery status.
-
When the detection is complete, issue the lsmdiskcandidate CLI command
to show the unmanaged MDisks. These MDisks have not been assigned to a storage pool.
-
Issue the lsmdisk CLI command to view all of the MDisks.
Results
You have now seen that the back-end controllers and switches have been set up correctly and
that the system recognizes the storage that is presented by the back-end controller.
Example
This example describes a scenario where a single back-end controller is presenting
eight SCSI LUs to the system:
- Issue detectmdisk.
- Issue lsmdiskcandidate.
This output is
displayed:
id
0
1
2
3
4
5
6
7
- Issue lsmdisk -delim :
This output is
displayed:
lsmdisk -delim :
id:name:status:mode:mdisk_grp_id:mdisk_grp_name:capacity:ctrl_LUN_#:controller_name:UID:tier
0:mdisk0:online:unmanaged:::68.4GB:0000000000000000:controller0:20000004cf2422aa000000000000000000000000000000000000000000000000:
1:mdisk1:online:unmanaged:::68.4GB:0000000000000000:controller1:20000004cf1fd19d000000000000000000000000000000000000000000000000:
2:mdisk2:online:unmanaged:::68.4GB:0000000000000000:controller2:20000004cf242531000000000000000000000000000000000000000000000000: