1. Can I migrate these 2 VM's from the AMD to the Intel, without it damaging/destroying the VM? Whatever the answer may be, can you please explain to me the why? Is the answer to the CPU migration dependent on the Guest OS or what? I ask because I've performed this successfully on a Windows Guest OS VM, but I guess it being Cisco makes me hesitant/question.
You should be able to perform a cold migration. The concern is at the guest OS level. The Cisco appliance is likely a Linux distro. The distro should use the AMD64 instruction set (Intel 64 compatible) and theoretically should migrate fine. However, if the guest OS has been passed enhanced instructions from the AMD processor, it may expect those features upon reboot. We do have at least one VM in our environment that we have to stick to a certain family of Intel processor because the software license digs and binds to it, but this is the only scenario I have come across.
2. Would it be better to have each of the VM's rebuilt on the new host, rather than go through the migration for the CPU purposes?
I'd feel better about redeploying, but if the migration succeeds and the applications run stable, then you just reaped the benefits of virtualization.
3. What is the recommended way of backing these VM's up, prior to proceeding with the migration? I am not talking about backing up for the sake of the data within Call Manager, as I will complete a backup there first. I am asking more along the lines of - for the sake of the VM itself.
You could do something as simple as cloning a copy. Depending on how you are licensed for vSphere, you may have VDP to back up your VM. You could also use a tool such as VMWare Converter or Veeam Backup and Replication. Given the criticality of these VM's, I'd get at least 2 backups of different type. You should be able to validate any backup with VMWare Workstation before proceeding with your migration.
