VMware GSX Server 2.5.2

 Prev   Contents   Last   Next 

The first configuration parameter users can set is the size of the virtual machine's physical memory. This configuration parameter can be set via the Configuration Editor (Settings > Configuration Editor > Memory). The minimum size of the memory for the virtual machine should be set based on the recommendations of the operating system provider.

The New Virtual Machine Wizard (on Windows hosts) or Configuration Wizard (on Linux hosts) sets what VMware believes are reasonable defaults for the memory size of a virtual machine based on the type of the guest operating system and the amount of memory in the host computer.

The actual size that should be given to a virtual machine depends on a few practical considerations:

• What kinds of applications are to be run in the virtual machine

• What other virtual machines will be contending with this virtual machine for memory resources

• What applications are going to be running on the host at the same time as the virtual machine

Windows operating systems do not behave well when they run low on free memory. For this reason users should not run virtual machines whose memory requirements exceed that of the host and other applications. To help guard against virtual machines causing the host to thrash, GSX Server enforces a limit on the total amount of memory that may be consumed by virtual machines:

The sum of the memories of all currently running virtual machines plus overhead for the GSX Server processes cannot exceed the amount of physical memory on the host minus some memory that must be kept available for the host.

Some memory must be kept available on the host to ensure the host is able to operate properly while virtual machines are running. The amount of memory reserved for the host depends on the host and the size of the host's memory.

If you want the most memory out of your virtual machine and are pushing close to the supported limits, you should expect that if you run the virtual machine for a while, power it off and change settings in the Configuration Editor (especially increasing the virtual machine's memory size), then try to power it back on, the virtual machine may not power on. If this happens, close the console in which you tried opening the virtual machine, and open a new console. The virtual machine should power on.