How it works…

Once CPU hot add and memory hot plug have been enabled on a virtual machine, it will not be necessary to power off the virtual machine to add additional vCPUs or additional memory.

Although vCPUs and memory can be added while the virtual machine is running, once Hot Add (or Hot Plug) has been enabled, some operating systems may require for the guest to be rebooted before the added vCPUs or memory are recognized by the operating system.

Enabling the CPU hot add and memory hot plug features does increase the virtual machine overhead reservation slightly. Also, remember that when a virtual machine's memory is increased, the virtual machine swap file (.vswp) also increases to the size of the allocated memory (minus any memory reservations). The swap file automatically grows when the virtual machine's memory is increased.

CPU resources do not have to be added in twos. If a virtual machine requires the resources that are associated with three CPUs, three vCPUs can be assigned to the virtual machine. It is also not necessary to allocate virtual machine memory in GB increments; a virtual machine can be allocated 1,256 MB of memory if that is what is necessary to meet resource requirements.

With CPU hot add and memory hot plug enabled, the removal of vCPUs and memory from a virtual machine will still require that the virtual machine be powered off or that the operating system be rebooted before the resources are removed, or before the removal of resources is recognized by the guest operating system.

Table of Contents for How it works&#x2026;

Create new playlist

Sign In

Sign Up

Table of Contents for
How it works…