I had TFS 2012 and I wanted to upgrade it to 2015. According to the MSDN website this shouldn't be a problem, except when I do it (...)
Before I started I made backups of the configuration database and the project collections. I downloaded TFS 2015 and executed the setup, allowing the setup to upgrade my 2012. It resulted in an error and I lost everything (except for the backups of course).
I didn't panic at all and thought: I will remove 2015, reinstall 2012 again and put back the backups. Good thinking, right? Except for the point that I ran SQL 2014 and the installation of TFS 2012 does not allow SQL 2014 (What the... ?).
(Re)installing SQL 2012 had no point either, since the backups where made in 2014.
Still no panic...
Next thing I tried was to reinstall SQL 2014 and TFS 2015. Setup the collection I needed and tried to restore the backed up database... The only thing I saw were errors. Atleast I tried, right?
So, here I am... A little panic has submerged now.
Is there any way to get all the information stored in the back (SQL 2014 database for TFS 2012) to my TFS 2014 environment?