User`s guide

Troubleshooting and Limitations 232
Memory Usage Problems
The amount of the host computer physical memory required for each virtual machine operation
can be represented as follows:
Virtual Machine Memory = Guest OS Memory + Video Memory + Virtual Machine Monitor
Memory
 Guest OS Memory is the amount of RAM available to your guest OS. You can configure the
guest OS memory amount in the Virtual Machine Configuration dialog.
 Video Memory is the amount of physical memory available to the virtual machine's video
card. You can adjust the video memory amount in the Video pane (p. 197) of Virtual
Machine Configuration.
 Virtual Machine Monitor is the
module responsible for the guest operating system
virtualization. It consumes memory to perform operations of guest virtual devices and
performs virtual paging emulation. The amount of memory required for the Virtual Machine
Monitor operation depends on the guest OS and varies from 50 MB to 200 MB.
Memory Overcommitment
If you have several virtual machines running simultaneously and you are trying to start one more
virtual machine, you may come across the memory over commit. The application will inform
you with the corresponding message. If you start one more virtual machine, this may
significantly slow down all your virtual machines. To solve this problem, you can:
 Stop one or several of your running virtual machines; or
 Edit your virtual machines' configurations so they consume less memory.