You can change the disk resources for a virtual machine. If multiple virtual machines access the same VMFS datastore and the same logical unit number (LUN), use disk shares to prioritize the level of access that virtual machines have to resources. Disk shares distinguish high-priority from low-priority virtual machines.

You can allocate the I/O bandwidth of the host to the virtual hard disks of a virtual machine. You cannot pool disk I/O across a cluster.

The shares value represents the relative metric for controlling disk bandwidth to all virtual machines.

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

You can select an IOP limit, which sets an upper limit for storage resources that are allocated to a virtual machine. IOPs are the number of I/O operations per second.


Power off the virtual machine.


  1. Click Virtual Machines in the VMware Host Client inventory.
  2. Right-click a virtual machine in the list and select Edit settings from the pop-up menu.
  3. On the Virtual Hardware tab, expand the hard disk to view the disk options.
  4. In the Shares drop-down menu, select a value for the shares to allocate to the virtual machine.
  5. If you selected Custom, enter a number of shares in the text box.
  6. In the Limit - IOPs text box, enter the upper limit of storage resources to allocate to the virtual machine, or select Unlimited.
  7. Click Save.