What is the default size of memory reserved for a VM's swap file?

The default size of the memory reserved for a virtual machine’s (VM) swap file is equal to the total allocated memory of the VM. This is because the swap file is used by the hypervisor to manage memory and to ensure that there is enough space to support memory overcommitment scenarios.

When a VM runs low on memory or when memory overcommitment is in effect, the hypervisor can use the swap file to temporarily store memory pages that are not currently in use. Thus, having a swap file size that is equal to the total allocated memory provides a necessary buffer that allows the VM to continue functioning smoothly, even when the physical memory is fully utilized.

This default behavior is important for virtual environments where memory management and performance optimization are critical. Understanding that the entirety of allocated memory is reserved for swap ensures that administrators can plan for adequate storage resources.

The other options do not accurately reflect the default behavior of VMware's memory management. While half the configured memory or a different metric might be considered in some contexts, the standard practice is to reserve the same amount of memory as allocated for the swap file.