Hi folks:
I'm getting ready to upgrade ESXi 6.7 to 7 and I'm trying to figure out the best and safest way to go about it. Right now 6.7, which has been upgraded over the years from originally version 4, is installed on a 4TB Raid 10 array along with the datastore. After reading about the partition changes that will happen with version 7, thus preventing any kind of roll back if there are problems, short of having a full 4tb sector by sector disk image of the whole array, I was wondering if it might be better to buy a half terabyte ssd drive and install ESXi 7 on that drive along with whatever minimal datastore it requires for the installation, and then simply mount the existing big datastore on the Raid array to ESXi 7, thus preserving the 6.7 installation and the partition layout just in case I have to back out.
The two potential issues that I see with this approach are first if ESXi 7 makes any changes to the datastore itself that would render it unusable by 6.7, and second I didn't think that one could backup the configuration from a prior release of ESXi and restore it to a freshly installed later version although I'm not 100% sure of that. I've been wanting for several years to divorce the datastore from the same physical drive as ESXi itself was on, as that might lend additional flexibility to take a full sector by sector image backup of the datastore partition while running copies of just a couple of the critical VMs that can't be down for a weekend (e.g. the email server) on another temporary datastore, which would be very difficult the way things are setup now, and so that would be another good reason to do this if I can make it work.
Thoughts and suggestions welcome.
