There seems to be a lot of fuss about HA not being reconfigured when Update 2 is installed.
The error message that appears:
“HA Agent on <hostname> in cluster <clustername> in <datacenter> has an error Incompatible HA Networks: Host has network(s) that don’t exist on cluster members: <ip address>: Cluster has network(s) missing on host: <ip address>: Consider using Advanced Cluster Settings das.allowNetwork to control network usage”
Pre-Update 2 environments would except incompatible networks between hosts in a cluster and just install/reconfigure. As of Update 2 this clearly isn’t the case any more, there are a couple of misunderstandings that I want to clear up:
If you have redundant service consoles set up they don’t need to be on the same subnet. (Better said, they should not be on the same subnet because of a bug described in this blog!) But they do need to be the same on every host. In other words you can’t mix up subnets, this will not work:
Host A – Service Console – 192.168.1.10
Host B – Service Console – 10.0.0.10
In this case you will need to change the IP-Address of Host B. Or add an additional Service Console named “Service Console HA” to both and filter out the first. You can filter out the first by setting the Service Console used for HA to a specific portgroup:
For more info read this topic and especially the reply that msevigny posted. The knowledge base article Marc points out to in his post is an internal one, as soon as it’s officially released I will let you guys know.
Scott Lowe says
Duncan,
Great post. One clarification: not only do redundant Service Console interfaces not need to be on the same subnet, they in fact SHOULD NOT be on the same subnet. This was one of the key things I pointed out in a recent HA configuration article:
http://blog.scottlowe.org/2008/07/11/vmware-ha-configuration-notes/
If you do place your redundant Service Consoles on the same subnet, they won’t work properly due to an IP routing issue that will attempt to route all the traffic across vswif0 even when vswif0 is down.
Duncan says
I know scott, I blogged about that one a few months ago: http://www.yellow-bricks.com/2008/01/14/service-console-redundancy/
But indeed should have emphasized this more so people don’t make that same mistake again!
benjamin says
VMware released KB article on this topic:
http://kb.vmware.com/kb/1006541