This week I took upon myself the challenge to upgrade our TFS 2005 SP1 single-server installation to the newly released 2008 version. When I was first introduced to our Team Foundation server it was running Beta 3 of TFS 2005. Since then it has mysteriously become my duty to upgrade to 2005 RTM, 2005 SP1, and now 2008 RTM.

I have gathered much needed experience on my previous upgrades to know how hard it would probably be. Beta 3 was originally running on SQL Server 2005 Developer Edition and the TFS beta wasn’t the Workgroup Edition. Needing to upgrade the beta database structures, switch the edition of SQL Server, and even migrate the whole lot to another physical machine has given me the confidence to deal with any TFS install.

I prepared for the 2008 upgrade by backing everything up, running the Best Practices Analyzer, then following the pre-upgrade checklist to the letter. So far everything is great. I inserted the TFS 2008 media, and began the setup. The setup prescan said everything was ok. It detected the existing installation, asked me for a few more settings (account passwords and mail server) then performed the upgrade.

Smooth. No errors. Database schema upgrade succeeded. And it was quick too. Again, I followed all the post-upgrade checklist items one-by-one and I was almost giddy at how easy it all was. I went back to my developer workstation and played around with work items and checked out and in some files. Perfect! I was so happy I went and upgraded our build servers too.

The next day my work colleague tried to undo a pending change and received a nasty error. The undo was failing and crashing the version control component on the server. I chased it down to the prc_iiUndoPendingChanges stored procedure experiencing a collation mismatch. The proc is encrypted but with SQL Profiler I was able to verify that it was a clashing collation between the TfsVersionControl database and SQL’s tempdb database.

How do you change the collation on the tempdb database to match the others? You don’t… you change the collation on the master database. How do you change the collation on the master database? You drop all your databases, rebuild the master using setup.exe on the SQL install media, then put all your databases back.

Still not that easy though. TFS 2008 requires SQL Server SP1. If you rebuild the master database with the RTM media you get an RTM master database. You can’t get or make SP1 slipstreamed install media and you can’t reapply SP1 after rebuilding master because all the other parts of SQL are already patched.

So, in the end you backup all your databases, uninstall all of SQL Server, reinstall it with the right collation, reapply the service pack, restore all your databases, rebuild the data warehouse and generally do all the rest of the necessary steps.

It was almost the perfect upgrade. Unfortunately collation settings were missed by the TFS team on one of their temp table definitions, it wasn’t picked up by testing, dogfooding, or the beta program, and I get all this hassle.

Still, all the new features in TFS 2008 make it worth it and I’d do it again. And will probably have to.