So this past week or two I’ve been playing quite heavily with Citrix XenServer and found it has a few little quirks that weren’t fully documented anywhere.
The first problem I had was in live migrating VM Guests between 2 servers. Usually this should be a straight forward drag and drop type operation, however trying it saw the guest say it was migrating and then proceeded to just hang for approximately 15 before minutes finally returning some obscure error code. It would happily start the VM on either server and I could ping and connect to both servers so I knew all the connectivity was OK.
MTU sizes mismatch
PV Network “card” tcp offsets
Can’t change network settings while in HA mode.