If multiple virtual machines access the same VMFS datastore (and therefore the same LUN), use disk shares to prioritize the disk accesses from the virtual machines. Disk shares distinguish high-priority from low-priority virtual machines.


Start a vSphere Client and connect to vCenter Server.


Select the virtual machine in the inventory panel and click Edit virtual machine settings from the menu.


Click the Resources tab and click Disk.


Double-click the Shares column for the disk to modify and select the required value from the drop-down menu.

Shares is a value that represents the relative metric for controlling disk bandwidth to all virtual machines. The values Low, Normal, High, and Custom are compared to the sum of all shares of all virtual machines on the server and, on an ESX host, the service console. Share allocation symbolic values can be used to configure their conversion into numeric values.


Click OK to save your selection.


Disk shares are relevant only within a given ESX/ESXi host. The shares assigned to virtual machines on one host have no effect on virtual machines on other hosts.