The advanced VMkernel.Boot.isPerFileSchedModelActive parameter controls the per file I/O scheduling mechanism. The mechanism is enabled by default.

1

Browse to the host in the vSphere Web Client navigator.

2

Click the Manage tab, and click Settings.

3

Under System, click Advanced System Settings.

4

Under Advanced System Settings, select the VMkernel.Boot.isPerFileSchedModelActive parameter and click the Edit icon.

5

Select one of the following options:

To disable the per file scheduling mechanism, change the value to No.

Note

After you turn off the per file I/O scheduling model, your host reverts to a legacy scheduling mechanism that uses a single I/O queue. The host maintains the single I/O queue for each virtual machine and storage device pair. All I/Os between the virtual machine and its virtual disks stored on the storage device are moved into this queue. As a result, I/Os from different virtual disks might interfere with each other in sharing the bandwidth and affect each others performance.

To reenable the per file scheduling mechanism, change the value to Yes.

6

Reboot the host for the changes to take effect.