@nikade Sure.
I have 2 mini machines running as XCP hosts, decided to upgrade them to newer hardware as they were struggling. I have:
XC1 - Brand new pool master on pool XC1
XC2 - Brand new pool slave on pool XC1
XCP1 - Old pool master on pool XCP1
XCP2 - Old pool master on pool XCP2
Installed XCP on both the new hosts, imported to Xen Orchestra, designated the first as pool master, added the second to the pool. Performed updates, did some nominal checks and called them good. Wasn't ready to migrate my VMs yet so powered both off.
Came yesterday, I unplugged my old hosts and set them aside, plugged in my new hosts (this is onto my UPS supply) power and network. Plugged in my old hosts to my temporary working area to migrate VMs. Powered everything on (old then new). XO stayed online the whole time, though DNS is on a VM that went down.
Only a single host came up (XCP2 - slave of XCP1). XCP1 had to be rebooted 3 or 4 times before it finally came alive but at a big ping delay (4ms, usually <1ms). XC1 and XC2 never came alive, their NICs had physical activity but got nothing. Eventually plugged in a monitor (awkward so didn't do it immediately), rebooted them both and saw no network configuration on either, just empty. Found this thread and decided, as they were basically fresh, I would just re-install and start over. Eventually got everything back.
I am assuming based on this thread that XC2 may have come up before XC1 and thus couldn't connect so it obliterated itself. Don't know why XC1 also did the same.
During testing I powered both XC1 and XC2 on and off multiple times without this happening, it was only when I powered everything on after moving them that it occurred. Thought I was going nuts or had caused a major network loop somehow.
