Storage Manager for SANs includes the Assign LUN Wizard, which you can use to assign a logical unit number (LUN) to a server or cluster.


If two or more Fibre Channel ports or iSCSI initiator adapters have been enabled on the server to which the logical unit number (LUN) will be assigned and the server is not configured to use Multipath I/O, data corruption can occur. For more information about Multipath I/O, see Support for Multipath I/O (MPIO).


If you want to assign the LUN to a cluster, make sure that the cluster has been properly configured, or data loss can occur. For more information, see Define a Server Cluster in Storage Manager for SANs.

Membership in the local Administrators group, or equivalent, is the minimum required to complete this procedure. Review details about using the appropriate accounts and group memberships at

To assign a LUN
  1. In the console tree, click LUN Management.

  2. In the Results pane, select the LUN you want to assign.

  3. In the Actions pane, click Assign LUN.

  4. Follow the steps in the Assign LUN Wizard pages.

Additional considerations

  • Before you assign a LUN to a server or to a cluster, you must first configure the connections on each server that will access the LUN by using the instructions in Manage Server Connections.

  • If the LUN that you want to assign is on an iSCSI subsystem, this LUN must be assigned to an iSCSI target. A server or cluster will only have access to that LUN after the iSCSI initiator on that server or cluster logs on to the iSCSI target. For information about iSCSI targets, see Manage iSCSI Targets.

  • If the LUN that you want to assign does not already have a volume on it, the disk associated with that LUN will be visible to the server that you assign it to, but it will be offline. Before you can create a partition or volume on that disk, you must first use Disk Management or DiskPart to bring the disk online. For more information about bringing a disk online, see:

  • You can use the Assign LUN Wizard to reassign a LUN that is currently assigned to a server or cluster. (The current assignment will be lost when the new assignment takes place.)

  • If you want to temporarily make a LUN invisible to a server or cluster, you can unassign the LUN. (In LUN Management select the LUN you want to unassign. Then, in the Actions pane, click Unassign LUN.) You will be able to assign the LUN again at a later date.

Additional references