Issues with Fake Raid

when using mdraid (multiple disks) 
[BIOS RAID disabled, using Linux softRAID]
# fdisk /dev/md
tecnicambalandia...ubuntu-on-fakeraid

Source
when using diskmapperRAID (FakeRAID)
ls -l  /dev/mapper
# dmraid -r
/dev/sdc: isw, "isw_feacijab", GROUP, ok, 976773166 sectors, data@ 0
/dev/sdb: isw, "isw_feacijab", GROUP, ok, 976773166 sectors, data@ 0

# dmraid -ay
# fdisk /dev/mapper/isw_feacijab_Volume0
or
# fdisk /dev/mapper/nvidia_ehffdafd
or
# fdisk /dev/mapper/dm-0
# dmraid -s
*** Group superset isw_feacijab
--> Active Subset