Control mounting ReFS volumes on USB and IEEE 1394 disks

Controls whether ReFS volumes are allowed to mount on disks attached by USB or IEEE 1394. ReFS is not a supported configuration on hot-pluggable or removable disks.

Block refuses the mount and records an event in the System log.

Audit only allows the mount and records the same event, so the effect of enabling this policy can be assessed before it is enforced.

Off performs no auditing and no blocking.

For a Storage Spaces volume the check applies to the physical disks backing the pool, not to the space itself.

If this policy setting is not configured, the local setting on this computer is used. If no local setting exists, the default behavior for this version of Windows is used.

ReFS reads this setting when it loads, so a restart is required before a change applies. The setting is then evaluated each time a volume mounts, so a volume that is already mounted keeps its current state until it is dismounted and mounted again.