Do you think that me using 512MB of ram for my VM Base memory with Windows XP when I am running 2.7GB of ram is okay? or should I return it back to 192MB?
According to Ubuntu reqs it would be enough if You have left for it 1GB of RAM. For example I have done something like this:
I have got a PC with 4GB of RAM, host is Ubuntu and the Guest is Windows 7. When I need to use Windows it means I need Windows at the moment, and not Linux, so my Win7 WM has 3GB of ram. The Linux is just working to run VM. But I don't run any apps on Linux in such situation.
For me such solution works really fine. So I think You could even enlarge the amount of RAM given to Your XP machine if necessary.
That completely depends on what else you run at the same time, but it should be fine. Track your Linux memory usage with
When the OS runs out of actual RAM memory (which is, relatively speaking, blazingly fast), it has to use swap memory, which is a file or a dedicated partition on your harddrive (which is really slow, relatively speaking -- hundreds of times slower than RAM). Obviously, you don't want your system to run into this situation. Hypervisors (the programs that host virtual machines) tend to allocate the whole amount of RAM that you set aside for the virtual machine since allocating it bit by bit (what normal programs tend to do) would negatively impact the performance of the virtual machine guest OS.
The output of
As you see, the swap is not used in this case ("used" is 0). This is fine. But if you run many RAM-intensive programs, such as Firefox with a bunch of tabs (especially ones with Flash content), an image editor, and your virtual machine together, then you might be taxing your system's resources. If you computer feels like it's getting slower, you now know where to check.
I would also like to comment on the reply that quotes Ubuntu's minimum system requirements: these do not take your running applications into account, so they refer to what you need to just get the basic Ubuntu environment up and running. Any application you run on top of that environment will also require resources.