Having recently implemented a CRM system where the enviroment has Multiple CRM servers pointing at the same database there are quite a few things to be aware of.
1.
The CRM Exchange Router will only support the receiving of Email to one environment. The service allows you to add an unlimited number of servers at install however it will only support the routing of incoming emails to the first server in the list. Other servers in the list will be supported for out going emails. This is only poses an issue if your CRM servers point to more than one database. In the case of multiple CRM servers on one production SQL implementation the primary CRM server should be added to the list for incoming emails and the remaining servers added for outbound. There will be no impact of functionality for end users but this will allow email to function on all CRM instances.
2.
The Crystal Reporting service returns errors "Unable to find file ... in file repository". When reports are published to the Crystal Enterprise system that is installed with Microsoft CRM, two things happen, first an entry is made in the APS database on the SQL Server that you chose during setup. Secondly the actual .rpt file is placed in a location on the server so that services can access and run the report for delivery to the client. By default, report files are located at C:\Program Files\Microsoft CRM\Crystal Decisions\Enterprise 9\FileStore.
When you install a secondary Microsoft CRM server is installed, reports are not republished. As a result, when the folder on the second Microsoft CRM server at C:\Program Files\Microsoft CRM\Crystal Decisions\Enterprise 9\FileStore is created, it is empty. At this point, if you tried to run any reports on the second Microsoft CRM server, you would see a list of reports, but you would not be able to open any of the reports.
There are two methods that will ensure that reports accessed from both Microsoft CRM servers are available, contain the same data, and carry forward any customizations that you may have applied to the reports that are shipped out of the box with Microsoft CRM.
1.Manually copy the files from server A to server B.The easiest and quickest way to make reports available from both Microsoft CRM servers is to copy the file location C:\Program Files\Microsoft CRM\Crystal Decisions\Enterprise 9\FileStore from server A to server B.
2. Use File Replication. Deploy a third-party file replication service to maintain synchronization for both server's file directories. The limitation of this method is that changes to reports will be synchronized between servers based on the intervals that you set for the replication service. You may need to tweak this setting to find out which interval is right for you.
I'm sure I will discover more but at the moment they are some of the big ones.