The advanced VMkernel.Boot.isPerFileSchedModelActive parameter controls the per file I/O scheduling mechanism. The mechanism is enabled by default.
- Browse to the host in the vSphere Web Client navigator.
- Click the Configure tab.
- Under System, click Advanced System Settings.
- Under Advanced System Settings, select the VMkernel.Boot.isPerFileSchedModelActive parameter and click the Edit icon.
- Perform one of the following actions:
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/O between the virtual machine and its virtual disks stored on the storage device are moved into this queue. As a result, I/O from different virtual disks might interfere with each other in sharing the bandwidth and affect each other's performance.
To reenable the per file scheduling mechanism, change the value to Yes.
- Reboot the host for the changes to take effect.