Disk shares"Proportional share" method.
If multiple VMs access the same VMFS datastore and the same logical unit number (LUN), there may be contention as they try to access the same virtual disk resource at the same time. Under certain conditions, the administrator may need to prioritize disk access for specific virtual machines; this can be done using disk shares.
If you want to give priority to specific VMs when there is access contention, you can do so using disk shares.
Using disk shares, the administrator can ensure that the more important virtual machines get preference over less important virtual machines for I/O bandwidth allocation.
“Shares is a value that represents the relative metric for controlling disk bandwidth to all virtual machines. The values are compared to the sum of all shares of all virtual machines on the server.”
“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.”
Disk shares control the I/O operations per second (IOPS) that the virtual disk is allowed to take from the physical resource. The values are Low, Normal, High, or Custom, with the following relative share values:
- High: 2,000 shares
- Normal: 1,000 shares
- Low: 500 shares
To allocate the host disk’s I/O bandwidth to the virtual hard disk of a virtual machine via vSphere Web Client:
|1||Right-click a virtual machine in the inventory and select Edit Settings.|
|2||On the Virtual Hardware tab, expand Hard disk to view the disk options.|
|3||In the Shares drop-down menu, select a value for the shares to allocate to the virtual machine.|
|4||If you selected Custom, enter a number of shares in the text box.|
|5||In the Limit - IOPs box, enter the upper limit of storage resources to allocate to the virtual machine, or selectUnlimited.|