The state of a virtual machine can be saved to disk or memory. This operation is called Suspend to disk or memory. By default, the suspend button will save the virtual machine to disk without using Advanced Power Management (APM) features of the guest operating system. Use the Configuration Editor to modify for your virtual machine.
Suspend to disk allows you to save the current state of a virtual machine across reboots of your host operating system. With Instant Restore you don't have to wait for your virtual machine to boot up. Instead, you can quickly pick up work right where you stopped, with all the applications and documents you were working on open and ready for use.
Suspend to disk is also useful if you are running multiple virtual machines on a system with limited physical memory. When a virtual machine is suspended to disk, VMware Workstation releases the memory used by that virtual machine, making it available to other applications. Be aware, however, that it is possible you may not be able to resume a suspended virtual machine if too little memory is available.
Suspend to disk or memory is useful if you are running on a portable computer and wish to save power. If you suspend to disk, you may exit the virtual machine after suspending. If you suspend to memory, the saved state of the virtual machine is available as long as the virtual machine is powered on.
Suspend to disk or memory is also useful if the guest operating system consumes resources while idling (for example, Windows 95, Windows 98, and Red Hat Linux 6.0). If you suspend a virtual machine to disk, you may exit after suspending. However, if you suspend a virtual machine to memory, you must resume the virtual machine and perform an orderly shutdown before powering off and exiting.
Warning: If you power off or exit a virtual machine suspended to memory, you will lose all your work and possibly leave the guest operating system in a bad or unstable state.
The speed of the suspend and restore operations depends on how much has changed during your working session. In general, the first suspend will take a bit longer than later suspends.