Basically, I have an ESX v3.5 host that I need to upgrade to ESXi v5.1, but that needs to be done in a way that can be rolled back without too much hassle but I'm wondering if any setting/config files can be copied from the old ESX 3.5 installation to the new ESXi 5.1 one to save some manual work on the rebuild?
The host currently has a 500gb SAN LUN with 4 VM's running on it with ESX itself booting from two local disks in a mirrored RAID set.
I'll be doing a clean install of ESXi 5.1 onto a USB key as I will need to be able to roll back to ESX 3.5 if for any reason the upgrade isn't 100% successful.
With this in mind, for my first step, I plan on adding another 500gb LUN from the SAN as an additional datastore and once the VM's are shut down, I will copy the contents of the old datastore to the new one and then shut down the host, at which point I will be pulling the boot disks out and installing the USB key to install ESXi 5.1 to.
Once ESXI 5.1 is installed, I'll add the new LUN with the copied VM's as the primary datastore, which I am expecting ESXi to tell me I need to upgrade the VMFS file system to the current version (which I believe is irreversible, hence me doing it on a new datastore to leave the old one intact in the event of a rollback).
that way if i need to roll back, I can just pull the USB key and put the drives back in and boot up and we're back to where we were before I started.
So my question is, are there any files that I can copy from the old installation to the new one to save me having to manually configure the host once ESXi has been installed?
Specifically, I'm thinking of user accounts and passwords and networking, but anything to save some manual work would be great.
Also, does everyone agree that this is the safest way to do the upgrade and still allow for a simple rollback if it was required?
Thanks in advance for any help/tips.