Completing VMware vSphere upgrade to ESX5i: Datastores

Today I begin tackling the last piece of my vSphere 5 upgrade project.

The project was a long time coming.  I was previously running ESX (no i) 4.0 update 1.  Sadly, this was a fairly buggy version.  Many support calls to VMware, some of which featured unpleasant downtimes, came back to blaming the version of my operating system.  I was unable to upgrade due to our previous backup software being incompatable.  Then once my colleague migrated us to a new backup system, other projects on my plate delayed things.

What did the upgrade consist of?  First, I had to tackle vCenter.  I had to migrate off Windows Server 2003 to Windows Server 2008 R2 64-bit, then I could go from vCenter 4 to vCenter 5.  At that point, the time came to upgrade each host from ESX4 to ESX5i.  That process was fairly straight forward, albeit quirky.  I frequently had to reconfigure the network settings or mess with NTP settings.

Now that my 9 hosts are upgraded, the last piece of the puzzle: datastores.

My datastores were running VMFS3.  The current version is VMFS5.  The wrinkle to the upgrade is that there are benefits to rebuilding the datastores fresh, not upgrading them.  One of the key features to VMFS5 is a unified 1MB block size.  An in-place upgrade would not give me that feature.

So, any system partitions on my hosts, or any local disks, I am not touching.  For my shared storage on my SAN, where I can migrate data off to alternate datastores, I am rebuilding.

The procedure is as follows:

1. Storage vMotion any VMs off a VMFS3 datastore by:
2. Right click VM in vCenter, Migrate.  
3. Change datastore, Next.
4. Select your datastore, virtual disk format (same format as source, or do you want to change: thick lazy, thick eager, thin).  Use the Advanced button if your server has data spread across multiple datastores.  Hit Next when you have things as needed.  Then Finish.
5. Confirm the datastore is empty.  In Datastores and Datastore Clusters view, on the Summary tab, note the Number of Hosts Connected.  Ensure Virtual Machines and Templates is ZERO!
6. Right click datastore, making note of it's original name if you want to reuse that later, and select Delete.  Confirm removal operation with Yes.
7. vCenter tasks will show the Remove datastore task and then all affected hosts will initiate a Rescan VMFS task.  Wait for these to complete.
8. In vCenter, go to Hosts and Clusters view.  Select a host connected to the storage, and go to the Configuration tab and then Storage.  Click Add Storage...
9. Storage type of Disk/LUN, Next.
10. Select the LUN (or name, if you're not working with a SAN).  Hopefully you only have the one you just deleted earlier.  Click Next.
11. File System Version, VMFS-5.  That is why we're doing this!  Next.
12. Review operation.  Next.
13. Enter desired datastore name and Next.
14. Maximum available space, Next.
15. Finish.
16. The datastore will be recreated, and the hosts will initiate another Rescan VMFS command.  Once those complete, you're good to go.  In DaDC view, you may want to relocate the new datastore back into any folder hierarchy you originally had.  Confirm all hosts reconnected (on the Summary tab) and that you are at VMFS5 (on the Configuration tab, mine lists at VMFS 5.54).
17. Repeat the above Storage vMotion operations (steps 2 thru 4) and you're good to go.
18. Work with your backup software to ensure any steps required for backups are completed.

I hope to plug away at this for a few days and have my 50ish datastores all at VMFS5.  Then onto other things!