Someone told me that I just need to load the device-mapper module in kernel but I have no idea how to do that.
You don't have to. If you see what you're seeing,
*** Active Set
name : nvidia_ddfchifg
size : 3907092480
stride : 128
type : stripe
status : ok
devs : 4
spares : 0
you're already using dmraid. dmraid creates a device with a name like
/dev/mapper/nvidia_ddfchifg1 (assuming one partition, number 1) which you can mount with something like
mount -o ro -t ntfs /dev/mapper/nvidia_ddfchifg1 /mnt
assuming you want read only ntfs
The location of the dev/mapper/nvidia_ddfchifg1 might be slightly different in fedora.