Updating Exchange 2010 CAS on a Hardware Load Balancer

This is a quick follow-up post to my How To Apply Updates To Exchange 2010 post; it deals with patching a CAS array behind a Hardware Load Balancer (HLB).

Everything else in my previous post is the same aside from "drainstopping" the Windows Load Balancer part.

Each HLB model (Kemp, F5, etc.) will require different steps, but it'll have the same outcome.

Remove the CAS server from the Load Balancer

For the CAS server you're updating, you'll want to Disable the "real server" in the HLB console and wait for connections to close.

If you prefer not to wait, you can force connections to close, by Deleting the "real server" and then stopping Exchange Services by running this command in PowerShell:

Get-Service | where{$_.Name –Like ‘MSExchange*’} | stop-Service –Force

Then to start the services, run:

Get-Service | where{$_.Name –Like ‘MSExchange*’} | start-Service

To get the current service state to make sure they came back, run:

Get-Service | where{$_.Name –Like ‘MSExchange*’}

After you've killed the connections with either method, proceed with the updates.

When the updates are finished for that particular CAS, re-enable or add it back into the HLB and move to the next one.