Server uses up all memory

The OS itself is probably using the rest.  This would be by design.  What's the point of having 4GB of RAM if you're not going to use it?

The problem I se here is that I do not know what the OS is using the memory for. The other problem is that if there is not memory left that I would assume the OS and apps are battleling over the memory. In my world a cpu usage of 95% is a concern.

The other concern I have is the fact that I limit the sal server to use only 2G of RAM - so what is the OS using 2G of RAM for? Is there a memory leak? Which app is it? Why is it not being displayed in task manager? As I said: That is concerning to me.

It would be useful if you could post a screenshot of Task Manager - performance tab. This would answer some important questions avoid much speculation.

I attached the screenshot of the 'performance' tab in the task manager. There is a good possibility that the server is simply overloaded and that this is what the problem here is. The thing what I am not able to explain so is the fact that the SQL server is limited to 2048 MB of memory usage and stll the server uses up almost all memory. But for what is it using the other 2G? I counted up all processes being run in the 'processes' tab and the server should use about 2.5 G and not all of.

I also attached a screenshot of the 'processes' tab in the task manager
task-manager---processes-tab.jpg
task-manager---performance-tab.jpg

The server is very busy. There is already a plan on the table to replace this 32Bit machine with a 64bit machine and move some or maybe all apps off.
I counted up the memory of th other tasks but they use up arround 256 MB not 2.0G. The memory usage varies a little. I have checked a couple times and the memory usage went down to 2.7G bu never lower. We could easily allocate more memory to the VM but I am worried that if I even double the memory of the server that it will use up all this memory as well.

So you do not think there is a issue like a memory leak or something? or an app which is acting up?

I don't suspect a memory leak at all - especially if the memory consumption goes down occassionally.  I expect SQL Server is doing what it does best and using all the resources at its disposal to run as well as possible.

Ok i believe ur judegment but then let me ask you why does the memory usage of the SQL server is not being reflected in the task manager. How can I determine what exactly is using up the other 2G because as I mentioned before the memory usage of the processes in the 'processes' tab use about 2.25 GB not 3.95G.

Well, 2GB of processes + 2GB memory allocated to SQL for its use = 4GB, right?

Yes the VM has 4G but again if I count the memory usage of all the processes in the processes tab in the task manager togehter then I get a total of 2.25G not 4G.

Yes, the applications are taking up about 2GB of RAM.  SQL Server is using the rest of it (because you've told it it can use up to 2GB) for caching tables, indexes, etc.  Total of 4GB-ish.

The 2.25G I was talking about include the SQL server service. 2G for SQl server and 256 MB for the apps. That is what the task manager displays.

Okay, maybe I'm wrong.  You can test it by configuring SQL Server to use less than 2048MB and see if that changes the system's memory usage.  My contention is that the 2048MB setting is in addition to the 1.645MB you see in the Task Manager.

We simply decided to build another machine with SQL Server 2008 64bit with more memory and more CPU resources and check if we can battle the problem this way.