Before Upgrading to App-V 4.5 SP2 on the management server, it is recommended to first review the release notes for added features such as SQL mirroring support.

App-V 4.5 SP2 Release Notes

http://technet.microsoft.com/en-us/library/ff699130.aspx

Also, you can download the installation for SP2 here:

http://www.microsoft.com/download/en/details.aspx?id=25291

Pre-Upgrade Recommendations

The following are recommendations for preserving information and critical data to ensure a proper rollback is available in the event of an upgrade failure or a desired rollback to a previous version of the App-V server.

1.)    Backup a copy of the App-V management SQL datastore. In SQL this is the APPVIRT database by default.

2.)    If .NET 4.0 is installed and you are using Windows Server 2003, The current work around is to:

a. Remove the .NET 4.0 (temporarily as it will be re-added later.)
b. Restart the server.
c. Perform the Upgrade. Restart the server.
d. Reinstall the .NET 4.0 Framework.

Potential Upgrade Failures

The following are recommended options for rollback should an error occur during upgrade.

In the event of a 25109 error, please use Rollback Option #1 for rolling back the server to its previous state.

In the event of a 25119 error (or any error not otherwise mentioned), please use Rollback Option #2 for rolling back the server and data store to its previous state.

In the event of a 2512* error, please use rollback option #3 for rolling back the AppVirt management Service (ASP.NET Web Management Service) to its previous state.

In the event that the installation completes successfully and you decide for reasons otherwise not mentioned here to roll back the server to its previous state, please refer to Rollback Option #2 for rolling back the server to its previous state.

Rollback Option #1

A 25109 error indicates failure to connect to the database. In the event of this error, all that needs to be rolled back are the binaries on the App-V Management Server.

1.)    After the installation rolls back, very connectivity to the App-V Management server.

2.)    If the binaries list version numbers at SP2 (4.5.3.XXX) uninstall the App-V Management server and reinstall your previous version.

Rollback Option #2

A 25119 error or a successful completion of the upgrade means that both the App-V Management server binaries and the SQL data store have been upgraded. The rollback procedure requires both the server binaries and the data store to be reverted back to its previous version.

1.)    Restore the previously backed up version of the App-V data store on the SQL server back to its previous version.

2.)    The App-V Management Server will likely be rolled back to its previous version during the installation. If this as a rollback following a successful installation then the existing version will need to be uninstalled and the previous version will need to be reinstalled.

Rollback Option #3

1. Manually uninstall ONLY the AppVirt Management Service (Service – not server.)

2. Restart the server.

3. Reinstall AppVirt Management Service component from SP2 media.