Migrate SQL Cluster LUNs from one array to another
We plan to migrate SQL cluster luns from one VNX array to another using EMC Openmigrator, below are the steps, can you please let me know if these are correct, we will also migrate Quorum drive with openmigrator
Open migrator version: 3.12
SQL/Windows Server - 2012
Create and assign new luns on new VNX SAN
Format the new drives ( SQL 64K)
Migrate data from active node - old VNX to new VNX (Drives – D,E,F,M,N,K,S,Q,R,T – K is Quorum disk
Before reboot of active node shutdown passive node
Reboot active node
Ensure all disks are visible with correct drive letters on active node
Start passive node, Check cluster working
Are above steps OK
What will be the rollback plan if there are issues, can we remove new VNX luns, re-assign/arrange drive letter of old VNX luns reboot servers?
All of your steps look correct, but I have two questions.
First, why not simply define a new Quorum disk? MSCS will let you select a new disk for the Quorum drive and will use it on its own. It just seems simpler than having a migration tool do it.
Second, have you considered using PowerPath Migration Enabler? If you're using PowerPath on your servers, PPME has a simpler rollback plan and allows you to move your devices one at a time or in groups. PPME is free, but will use CPU resources on the host to move the data. We were able to move a 2TB SQL LUN in about 90 minutes with the default settings and no noticeable impact on the server. You can always throttle a migration to reduce CPU impact or reduce the time needed to complete the migration.
Unless you're doing something very specific, Windows doesn't care about the Logical disk number, it cares about the disk signature. After you fail cluster disks from Node A to Node B, Node B activates the cluster disk based on signature, not logical disk number. If the disks are under cluster control, be sure to follow the steps for handling cluster disks, as per the guide.
Your steps for Open Migrator are correct. I would add that to attach Open Migrator filter driver to the source and target LUNs it would require a reboot. Also, to uninstall OM would require another reboot. I see Karl directed you to PPME which would be preferred as you can significantly minimize your downtime involved with this migration. Also, SANcopy would do the job if you needed an array-based approach. I almost prefer SANcopy incremental push over OM due to the number of outages I need to incur with OM.
Is there a reason you need to use -force with your powermig cleanup? I only ask, because I can't remember the circumstances it's required. In my experience, I have always put LUNs into a committed state before taking any further actions. I would not recommend removing drives once committed - that's what I would use powermig cleanup for.
If you're concerned about an issue that would force you to reverse the migration, I would go into TargetSelected for an extended period of time, and leave things like that for a while. We let a server stay this way for 30 days, to see the impact of month-end processing, then committed and cleaned up the migration. If we had issues during month-end processing, we were planning to use powermig abort and scrap the whole project.
umichklewis
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Posted February 17th, 2016 12:00
All of your steps look correct, but I have two questions.
First, why not simply define a new Quorum disk? MSCS will let you select a new disk for the Quorum drive and will use it on its own. It just seems simpler than having a migration tool do it.
Second, have you considered using PowerPath Migration Enabler? If you're using PowerPath on your servers, PPME has a simpler rollback plan and allows you to move your devices one at a time or in groups. PPME is free, but will use CPU resources on the host to move the data. We were able to move a 2TB SQL LUN in about 90 minutes with the default settings and no noticeable impact on the server. You can always throttle a migration to reduce CPU impact or reduce the time needed to complete the migration.
Let us know if that helps!
Karl