In this post I want to cover the Hybrid Configuration process - specifically detail on the Configure Legacy Exchange Support step.
The Hybrid Configuration Wizard has 6 tasks that it executes:
Lets cover the first two tasks where most of the problems usually occur (from what I’ve seen in the field).
Global prerequisites task – this task does the following checks:
Legacy Exchange Support task – This task covers legacy Public Folder configuration to allow Free/Busy lookup where Public Folder Databases exist in an organization. It can cause some major headaches if your Public Folder infrastructure is not healthy and the way it looks up Exchange servers in the organization.
Herewith the logic of this task:
I want to pause here for a moment and just highlight that the code executes Get-ExchangeServer and loops through each server. The impact of this is that your first Exchange 2010 server in the Get-ExchangeServer results will be the oldest Exchange 2010 server in your organization. Your brandspanking new Exchange 2010 Hybrid servers will be the last servers on this list. So be aware that if you have any firewalls between any of your Exchange Servers we need clear traffic between the Hybrid Servers and all the Exchange 2010 mailbox servers hosting Public Folders in that list – otherwise you might get the ‘Subtask ValidateConfiguration execution failed: Configure Legacy Exchange Support’ error. If the Hybrid Servers are your only Exchange 2010 Servers you need the Mailbox Role and Public Folder databases replicated to them for the above to work (see below).
It’s also important that your Public Folder infrastructure replication is working and healthy – otherwise you might experience problems with the Intall-FreeBusyFolder cmdlet.
The Mailbox role is a requirement on the Hybrid server in the event that you have Public Folders in the organization for Exchange 2003 mailboxes.
You will need to create a Public Folder database on the hybrid servers and ensure (force) that the hierarchy - \NON_IPM_SUBTREE folders and subfolders are replicated to this database by using AddReplicaToPFRecursive.ps1 script
The above isn't very detailed, but to understand the actual process and why the legacy step is so important in Exchange 2003 environments check out this great article from the Exchange Team.
Some more information on Hybrid Servers with Public Folders - http://technet.microsoft.com/en-us/library/hh757251(v=exchg.141).aspx
Remember to size your storage correctly for the Hybrid Servers if they will be hosting Public Folder Databases and the usual Public Folder guidance applies - http://technet.microsoft.com/en-us/library/bb629523(v=exchg.141).aspx
Hopefully the above can help with your troubleshooting steps if you receive the dreaded ‘Subtask ValidateConfiguration execution failed: Configure Legacy Exchange Support’ error during your Hybrid Configuration.
PS: And remember if your organization contains Exchange 2003 users, you must manually populate the TargetSharingEPR property (ex: https://hybrid.contoso.com/ews/exchange.asmx) on the Organization Relationship on the Exchange Online side :-)
UPDATE: The Exchange Team released the The Hybrid Free Busy Troubleshooter which is an awesome tool to help with Free/Busy issues - http://aka.ms/hybridfreebusy
Until next time,
With 2010 SP2/SP3, the ‘Subtask ValidateConfiguration execution failed: Configure Legacy Exchange Support’ will fail if you are attempting to run the command as an account that has a mailbox in the cloud. We also were able to successfully run the wizard on a Hybrid server without having the mailbox role installed on it for an all 2010 sp3 environment despite the existence of legacy public folders and this step still being executed.
Yes, in your case the wizard will still install the EXTERNAL Public folder in a native Exchange 2010 environment if the environment contains Public Folders. Your free/busy will also work, but the Hybrid servers won't have to intercept the Free/Busy call for 2003 clients, because you don't have any (that is actually the main reason to have the mailbox role installed on the Hybrid Servers - intercept Free/Busy PF queries for legacy mailboxes/clients that don't use the Availability Service). Every Free/Busy query in your environment will always use the availability service for lookups.
I've updated the article with some more info to help people understand why the legacy step is there and why you need the mailbox role on the server.
Thank you very much for this article. I was hitting #1 of Global prerequisites task at a customer and it helped me identify the issue. Please continue to expand on the rest of the steps. Its very valuable.
Thanks for the feedback. I'm very happy that the content helped you out. regarding the request for a part 2....stay tuned :-)