mhddfs не работает должным образом

Когда я бегу df -h Я получил:

Filesystem                       Size  Used Avail Use% Mounted on
/dev/sda2                         74G  3.0G   67G   5% /
none                             4.0K     0  4.0K   0% /sys/fs/cgroup
udev                             712M  4.0K  712M   1% /dev
tmpfs                            145M  1.2M  144M   1% /run
none                             5.0M     0  5.0M   0% /run/lock
none                             722M     0  722M   0% /run/shm
none                             100M     0  100M   0% /run/user
/dev/sda1                        511M  3.4M  508M   1% /boot/efi
/dev/sdb1                        1.9T   71M  1.9T   1% /mount1
/dev/sdc1                        1.9T   71M  1.9T   1% /mount2
/dev/sde1                        466G   26M  466G   1% /mount3
/dev/sdd                         466G   16M  466G   1% /mount4
/mount1;/mount2;/mount3;/mount4  4.6T  183M  4.6T   1% /NAS

Но, как вы можете видеть /NAS является 4.6T когда это должно быть 1.9T + 1.9T + 466G + 466G = ~ 5T!!

Вот так я креплю жесткие диски на /etc/fstab:

/dev/sdb1 /mount1       exfat defaults 0 0
/dev/sdc1 /mount2       exfat defaults 0 0
/dev/sde1 /mount3       exfat defaults 0 0
/dev/sdd  /mount4       exfat defaults 0 0

И на /etc/rc.local Я запускаю команду:

sudo mhddfs /mount1,/mount2,/mount3,/mount4 /NAS -o allow_other

Что не так?

sudo fdisk -l

из /dev/sde1 и /dev/sdd

WARNING: GPT (GUID Partition Table) detected on '/dev/sdd'! The util fdisk doesn't support GPT. Use GNU Parted.


Disk /dev/sdd: 500.1 GB, 500105740288 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976769024 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System

Disk /dev/sde: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/sde1               2   976773167   488386583    7  HPFS/NTFS/exFAT