Auto detection of Linux software RAID devices was lost in GParted
0.3.8. This was because device scanning by the libparted device
call ped_device_probe_all() was replaced with custom code within
GParted to scan /proc/partitions for devices.
The reason the libparted call was replaced was due to a long
scanning problem with ped_device_probe_all(), a non-existent
physical floppy device, and a BIOS setting indicating a floppy
drive existed. See bug #351753:
https://bugzilla.gnome.org/show_bug.cgi?id=351753
Curtis Gedak