vCenter: Don't forget the SQL Server Agent!

So this is one I learned the hard way: If you use SQL server for your vCenter installation, don't forget to start the SQL Server agent automatically!

vCenter installs rollup jobs which it needs to process the statistics to make it need less granular so it takes up less space.

These are called rollup jobs, and are controlled by the statistics in the vCenter server settings. I hear you ask: So what happens if I don't start SQL Server agent automatically?

Well.. Nothing, at first. But after a week, the statistics don't get rolled up, so the first table in the SQL database that is used for the statistics (VPX_HIST_STAT1) keeps growing and growing, and the data won't be processed into the next table, called VPX_HIST_STAT2, nor the next, etc. There are 4 tables. The last 3 tables will have no data, so when you look at the day, week, month or year statistics, you'll have no statistics. Starting up the SQL Server Agent quickly will give SQL time to roll up the data, but wait too long and you have too much data to process. There is a way to delete the data, described in this article, but you will lose all statistics.

So save yourself some trouble: If you are installing SQL Server for vCenter, don't forget the SQL Server Agent