Weird One on HyperV2012

[garethEds]

Weird one this week - reset one of our nodes in the HyperV2012 (have I got the terminology right?) and it came back up but had switched the main connection NIC to DHCP and removed the static IP address we had given it - so it lost connection to the other host.

 

In addition the virtual switches also lost their static ip addresses and switched to dhcp.

 

All because we restarted the server. Luckily we are not fully up and running yet (SAN arriving tomorrow I think). @rich_tech migrated the virtual machines over from the broken machine to the other one and it all worked fine. When we get the SAN hopefully this will happen automatically.

 

Anyone seen this sort of behaviour before?

 

Gareth

[rich_tech]

to give a bit more information now that I have had a chance to look at the logs, now the VMs are back up and working (nothing like exams server going funny the day before an exam) it appears to us that the 2nd HyperV host (Hyperv2) has had all its networking information seemingly go blank on rebooting it, as Gareth said, it then looks like it put the cards to DHCP and did not actually get any dhcp addresses from the network, it then gave the three NICs in operation on the machine automatic 169.254.x.x IP addresses, what it points to in the event viewer is lots of DNS and connectivity related issues.

This computer was not able to set up a secure session with a domain controller in domain XXXXXXXXX due to the following:

There are currently no logon servers available to service the logon request.

 

Was the critical error in event logs, but that seems to be after the IPs have been wiped then.

 

Restoring the IPs to their previous configuration seems to have remedied the issue for now and I have revalidated the cluster as of last night to check it and get all that working again and it seems to be fine, were just puzzled how a simple reboot has managed to take out the server over all.

[Michael]

I can't explain why you lost the static IP, but no DHCP leased IP due to DNS errors would make a lot of sense.