Michael Valentine Jones (2/11/2013)
I prefer to have the ETL (SSIS) installed on a different server because it is quite common to need to install or update additional software, controls, DLLS, etc. that might need a reboot, or that might experience a problem that will require a reboot.Also, you might need to have the ETL (SSIS) on a different version of SQL Server than the main database server.
This is an interesting point. At the moment we are running 2008 R2 across all the environments, but I'm wanting to investigate upgrading to 2012. Is it possible to run your ETL on 2008 R2 and your DBMS and Reporting Services environment on 2012? Well... I'm sure it is possible. But is it practical?
Being able to update systems progressively would certainly make the process less painful (if we decide to go ahead).