How to Reset the LUN Configuration

Use this procedure to completely remove and reset the LUN configuration.

If you reset a LUN configuration, a new device ID number is assigned to LUN 0. This change occurs because the software assigns a new world wide name (WWN) to the new LUN.

Steps

1. From one node that is connected to the storage array or storage system, determine the paths to the LUNs you are resetting.

   # format

   For example:

   phys-schost-1# format Searching for disks...done AVAILABLE DISK SELECTIONS: 0. c0t5d0 <SYMBIOS-StorEdgeA3500FCr-0301 cyl3 alt2 hd64 sec64> /pseudo/rdnexus@0/rdriver@5,0 1. c0t5d1 <SYMBIOS-StorEdgeA3500FCr-0301 cyl2025 alt2 hd64 sec64> /pseudo/rdnexus@0/rdriver@5,1

2. (A1000 Only) Is the LUN a quorum device? This LUN is the LUN that you are resetting.

   # scstat -q

   • If no, proceed to Step 3.

   • If yes, relocate that quorum device to another suitable storage array.

     For procedures about how to add and remove quorum devices, see your Sun Cluster system administration documentation. For a list of Sun Cluster documentation, see Related Documentation.

3. Does a volume manager manage the LUNs on the controller module you are resetting?

   • If no, proceed to Step 4.

   • If yes, remove the LUN from any diskset or disk group. For more information, see your Solstice DiskSuite/Solaris Volume Manager or VERITAS Volume Manager documentation.

     You must completely remove LUNs that were managed by VERITAS Volume Manager from VERITAS Volume Manager control before you can delete the LUNs.

     # vxdisk offline cNtXdY # vxdisk rm cNtXdY

4. On one node, reset the LUN configuration.

   For the procedure about how to reset the LUN configuration, see the Sun StorEdge RAID Manager User’s Guide.

5. (StorEdge A3500 Only) Set the controller module back to active/active mode.

   For more information about controller modes, see the Sun StorEdge RAID Manager Installation and Support Guide and the Sun StorEdge RAID Manager User’s Guide.

6. Use the format command to label the new LUN 0.

7. Remove the paths to the old LUNs you reset.

   # rm /dev/rdsk/cNtXdY* # rm /dev/dsk/cNtXdY* # rm /dev/osa/dev/dsk/cNtXdY* # rm /dev/osa/dev/rdsk/cNtXdY*

8. (StorEdge A3500 Only) Determine the alternate paths to the old LUNs you reset. Use the lad command.

   The RAID Manager software creates two paths to the LUN in the /dev/osa/dev/rdsk directory. Substitute the cNtXdY number from the other controller module in the storage array to determine the alternate path.

   Example:

   # lad c0t5d0 1T93600714 LUNS: 0 1 c1t4d0 1T93500595 LUNS: 2

   Therefore, the alternate paths are as follows:

   /dev/osa/dev/dsk/c1t4d1* /dev/osa/dev/rdsk/c1t4d1*

9. (StorEdge A3500 Only) Remove the alternate paths to the old LUNs you reset.

   # rm /dev/osa/dev/dsk/cNtXdY* # rm /dev/osa/dev/rdsk/cNtXdY*

10. On both nodes, update device namespaces.

    # devfsadm -C

11. On both nodes, remove all obsolete device IDs.

    # scdidadm -C

12. Move all resource groups and device groups off the node.

    # scswitch -S -h from-node

13. Shut down the node.

    For the procedure about how to shut down and power off a node, see your Sun Cluster system administration documentation. For a list of Sun Cluster documentation, see Related Documentation.

14. Perform a reconfiguration boot to create the new Solaris device files and links.

    If an error message like the following appears, ignore it. Continue with the next step.

    device id for '/dev/rdsk/c0t5d0' does not match physical disk's id.

15. After the node reboots and joins the cluster, repeat Step 7 through Step 14 on the other node. This node is attached to the storage array or storage system.

    The device ID number for the original LUN 0 is removed. A new device ID is assigned to LUN 0.