Hi Simon.

the RSExecRole wasn't something I ever really considered - most likley because I never encountered an issue with security and accessing the report server db.

As you mention it, my initial process was to install Reporting Services on both the servers that you want to use in the DR solution, following that i dropped one of the Reporting Server databases and then set up mirroring etc etc as per article. I believe as I done the standard install on both servers, it took care of the RSExecRole for me.

The area where you will need alot of consideration (and I haven't got around to doing this yet) is RS scheduled report jobs.

As the scheduled report jobs are created on th SQL server instance, you will need a mechanism for copy the Principle Report Servers scheduled report jobs to the backup server. I'll document this once I've done it, but my initial thoughts are to look at what jobs are listed in the report server db and those that are in the msdb sysjobs table, copying / deleted the sql agent jobs as appropriate.

let me know it I've not answered your question