BlackBerry Enterprise Server (BES) 5 includes a new High Availability (HA) feature, which can be used to install a standby server that is failed over to in the event of maintenance or a disaster. This can be setup for auto failover, or simply used to fail over manually if and when required.
The HA feature can also be used to perform a server migration to new hardware, using different server names, if you are upgrading or decommissioning your existing BES and/or hardware. The new server is installed alongside the existing BES and connected to the existing database, manually failed over, and then the old BES is uninstalled.
This article presumes that you have the existing SQL database installed on a separate server, in which case, no database prerequisites are required. If the database is to be moved to a new server too, this must be done beforehand:
KB03112 - How to move the BlackBerry Configuration Database to a new Microsoft SQL Server instance: http://www.blackberry.com/btsc/KB03112
KB18129 - How to change the BlackBerry Configuration Database in BlackBerry Enterprise Server 5.0: http://www.blackberry.com/btsc/KB18129
If you already have HA configured and have a standby server installed, the standby server will need to be uninstalled for the HA migration. This can be reinstalled once the migration has completed.
Backup the BESmgmt database using SQL Enterprise Manager.
Standby Server Installation
Start the BES installation and choose "Use an existing configuration database".
Select Remote and type the name of the server hosting the SQL database (unless you moved the database to the local server in the prerequisites above). The default database name is BESmgmt, which should be pre-populated.
Select to install as a standby server.
When the installer lists the existing BES servers, select the existing server that you are migrating from.
You can choose to keep the existing pool name for the BlackBerry Administration Service (BAS) or you can use a new pool name. If you keep the existing pool name, you must ensure the DNS entry for the BES you are migrating away from remains valid when it is uninstalled.
Once you have completed the installation, both Administration Servers are online at the same time and either administration address can be used to manage the servers. You can check this by browsing to the new BES server administration URL: newbes.yourdomain.local
Migration using High Availability
Using the BAS, navigate to Servers and Components > High Availability > High Availability Summary
You will see both of your BES servers in the list; the existing 'Primary' server and the new 'Standby' server.
Click on the Host Instance Name to be taken to the failover actions
Click on Manual Failover to switch the primary and standby servers
Once the page refreshes, check that the existing BES is now the Standby and the new BES is the Primary.
There may be a short delay whilst the BES servers fail over but, in a short time, the mail flow should continue as normal. This can be checked by doing an address lookup from a BlackBerry device, sending an email to and from a device, and checking that the event logs contain no critical entries (or ideally, warning entries too) regarding the BES services. If you do experience any errors after failover, simply fail it back to the original BES server and resolve the issues on the new server.
The existing BlackBerry Enterprise Server can be removed once the new server is confirmed to be working 100%. This can remain online for as long as necessary, or permanently stay online as a standby server for continuing high availability. If you do remove the old server, this must be done using the BlackBerry installer to correctly remove it from the configuration database and administration pool:
KB20020 - How to remove a decommissioned BlackBerry Enterprise Server from the BlackBerry Administration Service - http://www.blackberry.com/btsc/kb20020
I found this solution quite a simple method of moving the BES from one server to another, whilst maintaining the existing server to fail back to in case of any issues. The new High Availability features of BlackBerry Enterprise Server 5 are worthwhile implementing in your live infrastructure for things such as maintenance (e.g., Windows upgrades) and, of course, high availability.