How to Reset a LUN Configuration
Use this procedure to reset a storage array LUN configuration.
Caution - If you reset LUN configuration, a
new DID number is assigned to LUN 0. This change occurs because the software
assigns a new worldwide number (WWN) to the new LUN.
From one node that is connected to the storage array, determine the paths to the LUN. This LUN is the LUN that you are resetting.
f28c# format Searching for disks...done AVAILABLE DISK SELECTIONS: 0. c0t10d0 <SUN18G cyl 7506 alt 2 hd 19 sec 248> /sbus@3,0/SUNW,fas@3,8800000/sd@a,0 1. c1t5d0 <Symbios-StorEDGEA1000-0301 cyl 12160 alt 2 hd 64 sec 64> /pseudo/rdnexus@1/rdriver@5,0 2. c2t2d0 <Symbios-StorEDGEA1000-0301 cyl 12160 alt 2 hd 64 sec 64> /pseudo/rdnexus@2/rdriver@2,0Is 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.
Remove the LUN from disksets or disk groups.
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 from VERITAS Volume Manager control before you can delete the LUNs.
# vxdisk offline cNtXdY # vxdisk rm cNtXdY
On one node, reset the LUN configuration.
For the procedure about how to reset storage array LUN configuration, see the Sun StorEdge RAID Manager User's Guide.
Note - Use the format command to verify Solaris logical device names.
By using the format command, label the new LUN 0.
Remove the paths to the old LUN that you reset.
# rm /dev/rdsk/cNtXdY* # rm /dev/dsk/cNtXdY* # rm /dev/osa/dev/dsk/cNtXdY* # rm /dev/osa/dev/rdsk/cNtXdY*
Update device namespaces on both nodes.
devfsadm -C
Remove all obsolete DIDs on both nodes.
# scdidadm -C
Move all resource groups and device groups off the node.
# scswitch -S -h from-node
Shut down the node.
For the procedure about how to shut down and power off a node, see your Sun Cluster system administration documentation.
Perform a reconfiguration boot to create the new Solaris device files and links.
If the following error message appears, ignore this message. Continue with the next step.
device id for '/dev/rdsk/c0t5d0' does not match physical disk's id.
After the node reboots and joins the cluster, repeat Step 6 through Step 11 on the other node. This node is attached to the storage array.
The DID number for the original LUN 0 is removed. A new DID is assigned to LUN 0.
How to Correct Mismatched DID Numbers
Use this section to correct mismatched device ID (DID) numbers that might appear during the creation of storage array LUNs. You correct the mismatch by deleting Solaris and Sun Cluster paths to the LUNs that have DID numbers that are different. After rebooting, the paths are corrected.
Note - Use this procedure only if you are directed to do so from How to Create a LUN.
From one node that is connected to the storage array, determine the paths to the LUNs. These LUNs have different DID numbers.
# format
Remove the paths to the LUNs that have different DID numbers.
# rm /dev/rdsk/cNtXdY* # rm /dev/dsk/cNtXdY* # rm /dev/osa/dev/dsk/cNtXdY* # rm /dev/osa/dev/rdsk/cNtXdY*
Use the lad command to determine the alternate paths to the LUNs that have different DID numbers.
The RAID Manager software creates two paths to the LUN in the /dev/osa/dev/rdsk directory. Substitute the cNtXdY number from the other storage array to determine the alternate path.
For example, with this configuration.
# lad c0t5d0 1T93600714 LUNS: 0 1 c1t4d0 1T93500595 LUNS: 2
The alternate paths would be as follows.
/dev/osa/dev/dsk/c1t4d1* /dev/osa/dev/rdsk/c1t4d1*
Remove the alternate paths to the LUNs that have different DID numbers.
# rm /dev/osa/dev/dsk/cNtXdY* # rm /dev/osa/dev/rdsk/cNtXdY*
On both nodes, remove all obsolete DIDs.
# scdidadm -C
Move all resource groups and device groups off the node.
# scswitch -S -h from-node
Shut down the node.
For the procedure about how to shut down and power off a node, see your Sun Cluster system administration documentation.
Perform a reconfiguration boot to create the new Solaris device files and links.
Repeat Step 1 through Step 8 on the other node that is attached to the storage array.
Return to How to Create a LUN.



