Configure Storage Quality of Service (QoS)

If multiple virtual disks stored on a single physical disk, these virtual machines running simultaneously and accessing their virtual disks from the same physical disk，one virtual disk possible monopolize the physical disk's I/O,causing the other virtual disks to slow down. To help prevent this，you can control the Quality of Service（QoS）for a virtual hard disk.

You can open the Settings dialog box for a virtual machine in Hyper-V Manager, expand a hard drive component, select Quality Of Service, and select the Enable Quality Of Service Management check box on the Quality Of Service page. Now, you can specify minimum and maximum IOPS values for the virtual disk.

Note: Minimum and maximum IOPS are measured in 8 KB increments.

You can use the Set-VMHardDiskDrive cmdlet on Windows PowerShell to configure these setting.

VMName: virtual machine name

ControllerType: virtual hard disk controller type

ControllerNumber:  virtual hard disk controller number, Starting from 0