I moved four sites from Esxi to XCP-NG (there are about twenty ish virtual machines).
Once I figured out how to make XCP-NG work, it was relatively easy. I began by installing it on an unused old Dell.
My comments are from that standpoint of a general contractor (construction) that also does IT work so take some of my terminology with a grain (boulder) of salt.
Things that gave me some pause:
Figuring out how XOA works vs XO was somewhat confusing. I ended up watching two of Tom's videos at Lawrence Systems (shown below) to get me started.
https://lawrence.technology/xcp-ng-and-xen-orchestra-tutorials/
https://lawrence.technology/virtualization/getting-started-tutorial-building-an-open-source-xcp-ng-8-xen-orchestra-virtualization-lab/
NIC fallover - this was much easier in Esxi. It took me a night to figure out how to do the bonding thing.
The whole "NIC2:" has to be the same "NIC2:" on every machine was a pain in the a##. Again the way esxi does it is easier.
Figuring our the proper terminology to properly create a local repository
Find the disk ID of the βsdbβ or βcciss/c0d1βdisk
ll /dev/disk/by-id
use gdisk to create partions
"xe sr-create host-uuid=c691140b-966e-43b1-8022-1d1e05081b5b content-type=user name-label="Local EXT4 SR-SSD1" shared=false device-config:device=/dev/disk/by-id/scsi-364cd98f07c7ef8002d2c3c86296c4242-part1 type=ext"
Expanding an existing drive (i.e. after you grow a raid drive) was a tough (I have post on this site that shows how I did it).
Moving a VM from esxi to XCP-NG was just long and a few vomited in the process and had to be re-done. In some cases I used the built in XCP-NG migration and, in others (the huge VMs) I figured out how to do it via Clonezilla (much, much faster once I got the hang of it).
list item Having to shut down a running VM to increase the disk size is a bit of a PITA but its not that big of a deal.
Over committing memory...I still don't have a great grasp on the one.
Before I made the move, I did a ton of speed tests of esxi vs XCP-NG. About 60% were slightly faster on Esxi and 40% were faster on XCP-NG. In the end, the differences were negligible.
With all that said, I think XCP-NG is much easier to use than esxi and I like it better. Vcenter seemed to last about six months and then always died and had to be rebuilt (and the restore utility was about as reliable as gas station sushi). With XOA, it always works and is much faster than Vcenter.
The backup is awesome. With esxi I was using Nakivo.
Just my two cents!