Use mode=remove to disable disk mirroring. This option eliminates all references in the system tables to a mirror device, but does not remove an operating system file that has been used as a mirror.
If you set mode=remove:
The status column is altered to indicate that the mirroring feature is to be ignored.
The phyname column is replaced by the name of the secondary device in the mirrorname column if the primary device is the one being deactivated.
The mirrorname column is set to NULL.
