6.0

If the virtual machine memory is greater than the host memory size, swapping occurs, which can have a
severe effect on virtual machine performance. The memory size must be a multiple of 4 MB. The maximum
for best performance represents the threshold above which the host’s physical memory is insufficient to run
the virtual machine at full speed. This value fluctuates as conditions on the host change, for example, as
virtual machines are powered on or off.
Table 15‑2. Maximum Virtual Machine Memory
Introduced in Host Version Virtual Machine Version Maximum Memory Size
ESXi 6.0 11 4080 GB
ESXi 5.5 10 1011 GB
ESXi 5.1 9 1011 GB
ESXi 5.0 8 1011 GB
ESX/ESXi 4.x 7 255 GB
ESX/ESXi 3.x 4 65532 MB
The ESXi host version indicates when support began for the increased memory size. For example, the
memory size of a version 7 virtual machine running on ESXi 5.0 is restricted to 255 GB.
Procedure
1 In the vSphere Client inventory, right-click the virtual machine and select Edit Settings.
2 Click the Hardware tab and select Memory.
3 Adjust the amount of memory allocated to the virtual machine.
4 Click OK to save your changes.
Allocate Memory Resources in the vSphere Client
You can change the amount of memory resources allocated to a virtual machine by using the shares,
reservations, and limits settings.
A virtual machine has three user-defined settings that affect its memory resource allocation.
Limit
Places a limit on the consumption of memory for a virtual machine. This
value is expressed in megabytes.
Reservation
Specifies the guaranteed minimum allocation for a virtual machine. The
reservation is expressed in megabytes.
Shares
Each virtual machine is granted a number of memory shares. The more
shares a virtual machine has, the more often it gets a time slice of a memory
when no memory idle time is present. Shares represent a relative metric for
allocating memory capacity. For more information about share values, see
the vSphere Resource Management documentation.
Assigning a virtual machine a reservation larger than its configured memory is wasteful. The vSphere Client
does not allow you to make such an assignment on the Resources tab. If you give a virtual machine a large
reservation and then reduce its configured memory size on the Hardware tab, the reservation is reduced to
match the new configured memory size. You must power off the virtual machine before configuring
memory resources.
NOTE Virtual machine hardware versions 9, 10 and 11 features are read-only when connected to the ESXi
host or vCenter Server system using the vSphere Client.
vSphere Administration with the vSphere Client
150 VMware, Inc.