Adding a third node

[Logan Burt]

I have set up a Windows 2008 cluster running SQL 2008. I need to add a third
node to this cluster in order to support more SQL 2008 instances.

Is there anything more than simply adding a node? I thought I read
something in the past few months about a difference in the quorum between a
cluster with an even number of nodes vs. a cluster with an odd number of
nodes, but I haven't found anything now that I actually want to add a third
node.

Thank you.

[RCan]

Hi Logan,

absolutely ! And you are correct when you add a 3rd node to your cluster you
need to chance your quorum model to reach the majority in case of "murphy"
attacks ;-)
The new quorum model since Windows 2008 needs the build a majority of
"votes" to be operational.

In your case with 3-nodes (=odd) you need to use "node majority" which would
sustain an outage of 1 node
= When...
...1 of your 3 nodes goes offline cluster is operational
...2 of your 3 nodes goes cluster will stop !

References can be found here :
Failover Cluster Step-by-Step Guide: Configuring the Quorum in a Failover
http://technet.microsoft.com/en-us/library/cc770620(WS.10).aspx

Appendix A: Details of How Quorum Works in a Failover Cluster
http://technet.microsoft.com/en-us/library/cc730649(WS.10).aspx

Understanding Quorum Configurations in a Failover Cluster
http://technet.microsoft.com/en-us/library/cc731739.aspx

The quorum model can be easily changed within the failover cluster
manager -> Actions -> Configure Cluster Quorum Settings.

Hope that helps

Regards
Ramazan

Post by Logan Burt
I have set up a Windows 2008 cluster running SQL 2008. I need to add a third
node to this cluster in order to support more SQL 2008 instances.
Is there anything more than simply adding a node? I thought I read
something in the past few months about a difference in the quorum between a
cluster with an even number of nodes vs. a cluster with an odd number of
nodes, but I haven't found anything now that I actually want to add a third
node.
Thank you.

[Logan Burt]

Thank you very much! That is exactly the information I needed.

Post by RCan
Hi Logan,
absolutely ! And you are correct when you add a 3rd node to your cluster you
need to chance your quorum model to reach the majority in case of "murphy"
attacks ;-)
The new quorum model since Windows 2008 needs the build a majority of
"votes" to be operational.
In your case with 3-nodes (=odd) you need to use "node majority" which would
sustain an outage of 1 node
= When...
...1 of your 3 nodes goes offline cluster is operational
...2 of your 3 nodes goes cluster will stop !
Failover Cluster Step-by-Step Guide: Configuring the Quorum in a Failover
http://technet.microsoft.com/en-us/library/cc770620(WS.10).aspx
Appendix A: Details of How Quorum Works in a Failover Cluster
http://technet.microsoft.com/en-us/library/cc730649(WS.10).aspx
Understanding Quorum Configurations in a Failover Cluster
http://technet.microsoft.com/en-us/library/cc731739.aspx
The quorum model can be easily changed within the failover cluster
manager -> Actions -> Configure Cluster Quorum Settings.
Hope that helps
Regards
Ramazan

Post by Logan Burt
I have set up a Windows 2008 cluster running SQL 2008. I need to add a third
node to this cluster in order to support more SQL 2008 instances.
Is there anything more than simply adding a node? I thought I read
something in the past few months about a difference in the quorum between a
cluster with an even number of nodes vs. a cluster with an odd number of
nodes, but I haven't found anything now that I actually want to add a third
node.
Thank you.