Exchange Cluster setting Preferred Nodes

[umbletech]

Hi All

Just confirming my understanding. We have an AAP 3 node exchange 2003 cluster. We have two virtual servers that shouldn't try to run on one node.

In hklm\cluster\groups there were 3 guid instances:
5fd43bd1-4b60-4c47-b6ef-2cb8b587b475
This one had no AntiAffinityClassName set.

67dd35e9-a2f4-46fc-a6c8-5ad3c5e25426
e7b47872-3358-4b9b-a804-3958ec5a0ce8
These two had an AntiAffinityClassName of 'Microsoft
Exchange Virtual Server' set.

Now what I assume is that the last two GUIDs are those of the 2 active nodes and the Cluster service writes these values dynamically as the virtual servers move from node to node.

Is this how it works?

What I am unclear about is the priority. This page gives some guidelines - where does antiaffinity fit in these guidelines?

http://msmvps.com/blogs/clusterhelp/default.aspx

 

[umbletech]

Might have answered the second Q:

In the event of a failover, if a group being failed over has a non-empty string in the AntiAffinityClassNames property, the failover manager will check all other nodes. If there are any nodes in the possible owners list for the resource that are NOT hosting a group with the same value in AntiAffinityClassNames, then those nodes are considered a good target for failover. If all nodes in the cluster are hosting groups that contain the same value in the AntiAffinityClassNames property, then the preferred node list is used to select a failover target.

So basically its an override and if they all have 'Microsoft Exchange Virtual Server' set then it goes back to preferred owner.

 

[umbletech]

Hey all

Now I've got the other problem. I wanted to failover both virtual servers during a maintenance window and antiAffinity wouldn't let me.

Anybody know how to disable it without upsetting the cluster?