Refers to a RAID volume that was originally created in Windows NT Disk Administrator. These volumes include spanned volumes (volume sets), mirrored volumes (mirror sets), striped volumes (stripe sets), and RAID-5 volumes (stripe sets with parity). The FT refers to fault tolerant, even though some of the volume sets are not fault tolerant.
Windows Server 2003 and later versions of Windows does not support FT volumes; however, if you are running Windows 2000, SFW can maintain and repair these volumes, but it cannot recreate them. You can, however, upgrade a disk that contains these volumes to dynamic, and the volumes will be converted to dynamic volumes of the corresponding type. Versions of SFW that are earlier that SFW 5.0 provide support for this operation.