Question : Advice about moving master roles

Hi, me again.

The server that holds our FSMO roles is dieing.  Each time it goes offline so does our exchange server.  I've tried creating other global catalog servers but because there are 2 AD domains here with full trusts enabled, Exchange won't seek out a different domain controller.  (don't ask me why)  So I have to move the master roles to another domain controller.

Before I make a huge mess, is there anything I need to be concerned about regarding such an operation?  Is Exchange going to pick up the new server the roles have been moved to ok?  I do realize it'll take a while for propagation so I plan on doing this Friday evening.

Thanks!

Answer : Advice about moving master roles

Unless you hard-code the domain controller in the Exchange System Manager console, Exchange will pick the domain controller that it thinks is closest and/or responds the quickest (usually the least-busy).  When you transfer roles, Exchange SHOULD pick up the changes within 15 minutes, but it doesn't always work and it's frustrating to not know what dc it is using.  

To check on the dc's Exchange is using and/or hard-code it to use particular DC's, open the ESM, navigate to your Exchange Server's name and right-click, then select properties.  Once the Properties window comes up, select the Directory Access tab.  From the "Show" drop-down, select Configuration Domain Controller, then Domain Controllers, then Global Catalog Servers.  You will see the domain controller(s) discovered by Exchange and cached for use for each function.  To hard-code it, simply uncheck the "automatically discover servers" under EACH of the categories, then manually enter the dc's you want used for particular functions.  Any in-site DC is good to use in the Configuration Domain Controller and Domain Controllers, and any in-site GC is good to use for a GC.  Of course you should pick the least-loaded dc, since Exchange will generate some serious request traffic.  

My own preference is to run Replmon and the Exchange Best Practices Analyze's default Health report following any dcomain controller maintenance.  If those tools don't show you any critical problems after role transfer, you can safely assume Exchange is happy going forward.