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 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 handle 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.

You can configure the whole amount of physical memory available for all running virtual machines in the Memory tab of the application Preferences.

Memory Overcommitment

If you have several virtual machines running at a time, and you are trying to start one more virtual machine, you can come across the memory over commit. The application will inform you with the corresponding message. This means that all your running virtual machines require more memory that is configured in the Memory tab of the application Preferences. 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 to make them consume less memory, or
• edit the application memory preferences to allocate more memory to your virtual machines.