Thanks, I don't know how I missed that I was on that page multiple times today. It is kind of vague though.....and I might of just skimed over it since it says Other "Versions".........
I did follow that path and used the link to the following information: http://docwiki.cisco.com/wiki/Ongoing_Virtualization_Operations_and_Maintenance#Upgrading_ESXi
Upgrading ESXi
Multiple versions of ESXi are supported by UC applications.
To upgrade the ESXi software on a host, you must power off all virtual machines or migrate the virtual machine to a different host.
Instructions for installing or upgrading to a specific ESXi release are available in the release notes of the ESXi version you install. For example, here are the VMware ESX 4.1 Update 1 Release Notes.
After upgrading ESXi, or whever moving a virtual machine to a different host that is running a different version of ESXi, VMware Tools must be upgraded on the UC applications so that the tools versions shows "Up to Date" in the vSphere Client (see VMware Tools).
It is OPTIONAL to upgrade the VMV (Virtual Machine Version) version of the virtual machine to the newer VMV version. If you do upgrade to the newer VMV version, note that your virtual machine cannot be changed back to the previous VMV version, and that the new VMV version will NOT run on your older version of ESXi. For example, if you are running a vmv7 virtual machine on ESXi 4.1, and you upgrade to ESXi 5.0, you can optionally upgrade the vm to vmv8. Once you upgrade to vmv8, your virtual machine can only run on ESXi 5.0 and later. Once upgraded to vmv8, the virtual machine cannot be converted back to vmv7. For further information see VMware documentation.
Upgrading the UC applications
When running UC virtualized, it is necessary that the virtual machine configuration be set properly for the specific release of the UC application that you are running.
When doing a fresh install, it is required to deploy the OVA for the application that matches the release of the UC application itself. This ensures that the fresh install has the proper virtual machine configuration for the release being installed.
When a UC application is upgraded (eg. upgrading CUCM from 8.5.1 to 8.6.2), it is necessary to go to www.cisco.com and look at the Readme file for the OVA of the release you are upgrading to. For example: go to www.cisco.com and go to Support -> Downloads. From there Products -> Voice and Unified Communications -> IP Telephony -> Call Control -> Cisco Unified Communications Manager (CallManager) -> Cisco Unified Communications Manager Version 8.6 -> Unified Communications Manager Virtual Machine Templates-8.6(1)
When you're at the appropriate OVA, select "Download Now" and you will be taken to a page where you can click to view the Readme file. In the Readme file, you will see the virtual machine settings for the release. You must edit settings on the virtual machine you have upgraded to match the setting in the Readme file.
You will need to make the changes (edit settings) while the virtual machine is powered off. After you are booted up on the new software version, you must gracefully shut down the virtual machine, change the settings, and boot it back up.
There may be cases where there are no required changes. It will depend on the specific "from" and "to" versions of the upgrade.
Still not very in-depth but looks like you "can" leave the old OVA and stay on the vm version but as soon as you change it to next version or upgrade you have to use the new ova and it won't roll back......still not sure what the advantages are or any issues that may come about. I mean if ESX5.1 can run an upgraded vmv with a vm7 template, why did they even create a seprate vm8 template? Why is it optional? Guess that's one of those Cisco mysteries.
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Cisco UC Architect
