You can break or remove a mirror. It is important to understand the difference between these operations.

Breaking a mirror takes away a redundant mirror (or plex) of a volume and assigns it another drive letter. The data on the new volume is a snapshot of the original volume at the time of breaking. Breaking off a plex of the mirrored volume does not delete the information, but it does mean that the plex that is broken off no longer mirrors information from the other plex or plexes in the mirrored volume.

Removing a mirror from a volume "removes" or destroys the data from the selected mirror and leaves the other mirror or mirrors intact. After you remove a mirror, the space on the disk used by the removed mirror becomes unallocated free space.

The details on breaking and removing a mirror are included in the next two sections, "Break Mirror" and "Remove Mirror."