Tuesday, February 12, 2008

TFS 2005 to 2008 Upgrade Experience

I've been meaning to write something about this for awhile now. Friday the 11th of January we migrated our exsisting TFS environment from TFS 2005 to 2008. All in all it was a rather painless transition, the bumps we ran into where related to the fact that we are running our TFS installation on a different port than 8080.

The first issue though was an typo in the installation help. We figured it would be best to follow the latest version of the documentation. Before we started our upgrade we spotted that the documentation stated that you needed to remove TFS from the application tier on a single server installation which was not the case in the original documentation on the media. After some asking around we managed to come to the conclusion that this was only needed on the database tier in a dual server installation as the original instructions stated.

Even though we had performed numerous test upgrades we managed to forget the fact that we did not run on a different port in the test environment. The upgrade does not picked up the configuration settings from the previous installation and thus it tried to communicate with TFS on the default port causing it to fail miserably. At this time we had spent about 3 hours and where getting abit worried if we where going to have to perform an emergency restore.

So we gave it another shot and unpacked the image onto the local harddrive and modified the port settings in the msiproperty.ini (you will find it under the AT folder). Fortunately the upgrade of the database is performed transactionally and thus the database upgrade was rollback and we where able to perform that step again.

The fact that the database upgrade is quite a large operation is something you need to consider when upgrading since it consumes alot of diskspace. If you have a 15GB database you should expect atleast the same ammount to acumulate during the upgrade in your transaction log of your database. So make sure you have plenty of disk avaiable where ever you store your transation logs.

After we changed the port settings and ran again it took ages to perform the upgrade however it managed to get through it all and I where actually considering killing the upgrade and restoring to TFS 2005 but we started a database trace against the databases and managed to verify certain activity and let the upgrade continue. After about 6 hours we had managed to successfully upgrade our TFS installation.

After a month have passed we have still not encountered any major issues with the 2008 version and everything is running along smoothly. I will be posting some from the trenches posts on any issues we bump into.