I have a 13-host HA/DRS cluster, all hosts running ESXi 4.1.
I put one host in maintenance mode this afternoon, and once it migrated all the VM's, disabled its HA agent, and entered maintenance mode, suddenly several other hosts registered the error "HA Agent on the host failed". I immediately took the one host out of maintanence mode, and the errors cleared. All VM's stayed operations during this time.
This has happened to me before - I had to take a server offline due to a hardware problem and most of my hosts registered an HA error and attempted to fail over some VM's, but failed to do so (I just remember it failed to fail over the VM's, I don't have the event history for that, its been a couple of months).
Any ideas why putting a host in maintenance mode might break HA on my other hosts in the same cluster?
Thanks in advance.
jdptech