vMotion fails at 14% – ESX hosts failed to connect over the VMotion network

On a newly built host today vMotion was failing while migrating VMs to this host. vMotion would get stuck at 14% and then fail with the above error. Found this VMware KB article – it was informative but didn’t help. From this article I learnt though that I can use vmkping with the -I switch to specify an interface to use while pinging. This is handy when you want to ping a remote address via a specific interface – say, the vMotion IP address of a remote host, via the vMotion VMKernel of this host. Usually vmkping automatically selects an interface on the network you are trying to ping but it’s possible you are using the same subnet for vMotion and many other services.

Anyhow, in my case I noticed that if I removed one of the underlying physical adapters I am able to vmkping. So add that to the list of things to try if you too are in a similar situation. Odd though that it failed though! I would have thought a failed physical adapter means it will just try a different one? Clearly in my case the other adapter was working.

I don’t know more details but it could be that the physical NIC was up but the switch was blocking? Not sure.