With the new Virtualcenter 2.5 Update 2 comes some tighter restrictions on HA network configurations.  This error message commonly occurs when the nodes in a cluster contain incompatible networks. An attempt to reconfigure clusters might fail now if they do not have identical networks.
Some customer are reporting the message:

HA agent on <esxhostname> in [...]

As soon as Update 2 of Virtualcenter 2.5 hits the streets we started getting calls into support lines here at VMware about HA breaking.
Common reports include:
“insufficient resources to satisfy HA failover level on cluster” and “unable to contact a primary HA agent in cluster”
We think we know what is causing this, so I’m sharing this [...]

My previous article on HA failover capacity generated a bit of buzz and some discussion in the blogosphere. I have a few more details today which may clear some of the air on this.
A question was raised about the calculation used in admission control. I was previously under the impression that Configured Memory (in a [...]