What is the best practice or best migration when you want to transfer your storage from Compaq's StorageWorks to EMC's Symmetrix. I am just wondering the length of time and other things to do before the migration.
- In the new storage array, pre-configure your LUNs to match your current environment. Set any LUN security or switch zoning to provide access to an HBA in nodeB of the cluster.
- Insert a new HBA into NodeB in the cluster. If the server is already dual homed, connect one HBA to a SAN port that has access to the new storage array.
- Update the HBA drivers to the correct revision for the HBA connected to the new array.
- Reboot nodeB, and verify access to the new LUNs via NT disk admin, or on Win2k, under the manage disks MMC. Create an NTFS partition on the LUN configured for the cluster quorum resource in the new array, and do a quick format.
- Migrate ALL Cluster resources to nodeB.
- In cluster admin, create a new disk resource for the new quorum disk, and move quorum to the new disk. The cluster will now have all application resources on the old array, and have quorum configured for the new array.
- Install or move an HBA in nodeA, update the driver, and verify connection to the new LUNs. Shut down nodeA and power it off.
- On nodeB, go to control panel, and stop the cluster resources (Cludisk, and cluster service) and set the services to start manually.
- On nodeB, run disk administrator and document the disk labels, drive letters, and physical disk numbers for the existing cluster resource disks.
- On nodeB, run the registry editor and go to HKLM/Current control set/services/Clusdisk, and make note of the actual disk signatures assigned to the cluster resources. Document the physicaldisk and drive numbers for these drives. You will need this information so you don't delete the new quorum disk signature by mistake in step 12.
- On NodeB run disk administrator, and create a mirror set between the old resource disks and the new LUNs in the new array. The mirrors will now synchronize, and should take between 50-60GB per hour to complete. Once complete, remove the connection to the old disk array on nodeB.
- Reboot nodeB, go into registry editor, and delete the disk signatures from the ClusDisk registry entry for all disks EXCEPT THE QUORUM RESOURCE!!, if you delete the quorum disk signature by mistake, you are out of luck. Use the information gathered in steps 9 and 10 to determine the disk signature of the quorum disk. (If the signatures are not deleted here, you will never be able to get back to the same drive letters as the original cluster disks!)
- On nodeB, run disk administrator, and re-letter the new drives to the original drive letters documented in step 9. Go to control panel, and reset the cluster services to startup automatic.
- Reboot nodeB, and verify the cluster comes up normally.
- Reboot nodeA, and verify you can fail over resources to nodeA. (when nodeA reboots, it pulls the registry info for the new cluster disks from nodeB. The ClusDisk registry entries are rebuilt automatically by nodeB when it was rebooted). If nodeA has troubles coming up, evict the node from the cluster, de-install clusters from the node, and then rejoin nodeA back into the cluster with nodeB.
I hope this helps. I have used it a few times now, and it works like a champ. Win2k clusters are even easier and are really easy with VERITAS? VxVM installed.
This was first published in August 2001