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Help! SQL Server is eating my memory.

Some of my team members were complaining that Team Foundation Server was really slow. So assigned as the 'TFS guru', I was the ultimate victim to look into the issue.
As I logged on the TFS server (and waited a looooong time), I noticed in the Task Manager that CPU usage was rather normal but all the memory was used and an enormous page file was eating up the hard disk space.After som sorting magic on the Mem usage column I saw that sqlservr.exe was using all the memory. More than 2 gigs of Mem Usage seems a little bit over the edge.
There were two things that helped me investigate the issue.

The first one are following commands; DBCC MemoryStatus and DBCC MemUsage
Second you can have a look at the huge amount of SQL Server performance counters that can help finding the problem.

But these didn't help me to pinpoint the exact problem.

One of my colleagues suggested that SQL Server was probably using all this memory because it prefers caching the data in memory over doing a lot of disk I/O (which sounded logical). So I opened up the SQL Server Management Studio and had a look at the properties of the database server.
I browsed to the Memory page where I limited the Maximum server memory and everything worked smoothly.
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