Upgrade CUCM and IM&P from 12.0 to 12.5 and platform refresh

[stuart.pannell]

I am looking to do a CallManager and IM&P upgrade from version 12.0.1.22900-11 to latest 12.5(1) and also incorporate a platform refresh moving from current ESXi 6.0 to ESXi 7.0. I think that I can use PCD to perform the upgrade and migration though could do with some guidance for the best method. There are 2 options: -

1/ PCD migration and upgrade, I have done these in the past when migrating from physical to virtual and once the pre-requisites are met then they went quite smoothly. I think this is a good method and possibly my preferred option however I'd like to have your input?

2/ New install and data import, I presume this also uses PCD to build the cluster and import the data . I think this would be difficult given that I have a 24/7 user environment which is a hospital though I don't know what is really involved? I don't want to change my IP's if possible and I can't see a way of doing this without doing so.

I'd like to know the easiest method and also which one would have the least downtime? I have a cluster of 7 servers 1 pub, 3 subs, 3 back subs/tftp.

[Jonathan Schulenberg]

If this is a single cluster and you do not have ungraceful shutdown warnings (a PCD migration to new VMs cleans that up) I’d probably just do an in-place upgrade without PCD or anything. 

As for migrating the VMs to another host: you can either power them down (one at a time if 24/7) and then export/import in ESXi; or, if you have vCenter storage vMotion them to the other host. Just read the release notes and upgrade guide in case it wants you to tweak any of the VM settings (eg guest OS version).

If you like PCD there’s no technical reason to avoid it here; a migration task will get you to the same end result: newer version on new VMs running on different ESXi hosts. This is personal preference territory IMO.

PS- I’d skip 12.5 and go to the 14 unless you have a compatibility blocker. The .0 vs. .5 release strategy ended with 12.x. The current release train is 14 with an SU every 3-4 months on average. The next release will be 15 due late this year or early next. 12.5 is already the “trailing” release train at this point and will go end of sale as soon as 15 is released.