We have a sql 2005 x64 database running on Windows 2003 SP2 x64 on a virtual machine (I know this isn't ideal, but it's a business requirement). The server has 26GB of RAM allocated and we have set SQL Server's max ram at 16GB, analysis server at 7GB. Windows normally reports that we have about 2GB of free physical memory sitting around on the box.
For some reason today we only have about 100MB of free physical memory. There are no abnormal processes running and SQL Server and Analysis server are sitting just below their respective caps. We tried stopping and starting the sql server about 4 hours ago which freed up all the memory, however it's since dipped back down to 100mb. This is shown in Perfmon and Task manager
There are no obvious new processes running, and nothing consuming noticably more memory than normal.
It doesn't seem to be affectind database performance, however I'm concerned by this sudden unexplained change. No updates have been carried out since we restarted on Monday night. It's been running fine since then until today.
Can anyone suggest anything that I should check to find what's going on with the physical memory?