What to do with WMI errors and Team Foundation Server

Last week I spent some time on trying to sort out WMI errors in a test environment. That was not fun, but at the end of the day there is something to learn out of it.

Everything starts with this set of errors with an AT-only installation:

Looking at the logs you can see it is pretty bad stuff:

I tried with the usual suspects (wmimgmt /verifyrepository, setting the involved machines as standalone hosts, etc), but they all run fine. One of the suggestions you can find around is to reinstall the IIS 6 Management Tools on the Application Tier:

Still no luck. I tried connecting with wmimgmt.msc and I got all sorts of errors. At the end of the day I temporarily reset the WMI repository on that machine and I then decided to move these test services to another VM. Why?

The WMI repository is not supposed to be rebuilt lightly. It should be the last resort, and I did not want to tie up this testing environment with a potentially problematic machine.

Don’t forget that the Application Tier is just a front-end for Team Foundation Server. You can replace it with another machine and scale out as needed.

Also, the errors above appear in both the Application Tier and Data Tier readiness check category for the AT-only install, despite they only apply to the AT. That is because the machine could not communicate with anything beyond itself (not even itself I would add), so it would report that the Data Tier isn’t reachable. Do not touch the database servers unless you really have to, and the logs are going to tell you if you have.