Error creating a mount point on SQL cluster volume.
When you try to create a new mount point on existing cluster volume, you may not succeed. Sometime, it may throw error 11 or simply ignore. When, checked on cluster volume you may find the mount point missing. This is because the existing/running SQL will not allow certain administrative actions on disk.
In order to complete the request we would need to enable the Maintenance Mode. Putting the disk into maintenance mode simply disables a few disk checks the cluster service performs.