The Cisco IronPort virtual edition has been out for about a year now. It’s still not quite as mature as we would like for it to be; for example, it lacks support for Hyper-V, modifying the CPU core allocation to meet peak performance demands, etc.
One of the unsupported ‘configurations’ is virtual machine snapshots.
This is what I was advised by a TAC engineer:
“The software was written for physical hardware, and operations such as snapping an image and reloading it at a later point in time, is not supported.
Our appliances often have files open, and taking a snapshot while a file is being written, can leave you with a worthless snapshot, that can’t be executed. And thats only one of the problems you may encounter
I can confirm it is not supported, but nevertheless it will probably work when the machine is completely shut down. It will probably fail when the machine was ‘powered on’. There are no power states like pause or standby which would take the filesystem into a state that would be safe for a snapshot.
I can confirm, no problem if version mismatch due to a revert. A “revert” of the machine (CLI> revert) also results in such a mismatch, but this is automatically resolved.”
So as you can see, snapshotting your ESA isn’t technically supported HOWEVER if you follow the basic steps below you shouldn’t have any issues.