root@X3650:/# df
Filesystem      1K-blocks      Used  Available Use% Mounted on
udev              2013436         0    2013436   0% /dev
tmpfs              405068      6636     398432   2% /run
/dev/sda1        45586292  44282388          0 100% /
tmpfs             2025340         0    2025340   0% /dev/shm
tmpfs                5120         0       5120   0% /run/lock
tmpfs             2025340         0    2025340   0% /sys/fs/cgroup
/dev/sdb1        88874936  35925504   48391816  43% /home
tmpfs              405068         8     405060   1% /run/user/0
/dev/sdc1      5813235212 196499792 5323694628   4% /mnt/WD
tmpfs              405068         4     405064   1% /run/user/111

root@X3650:/# lsblk
NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda      8:0    1   50G  0 disk
├─sda1   8:1    1 44.4G  0 part /
├─sda2   8:2    1    1K  0 part
└─sda5   8:5    1  5.6G  0 part [SWAP]
sdb      8:16   1 86.6G  0 disk
└─sdb1   8:17   1 86.6G  0 part /home
sdc      8:32   0  5.5T  0 disk
└─sdc1   8:33   0  5.5T  0 part /mnt/WD
sr0     11:0    1 1024M  0 rom

root@X3650:/# du -h --max-depth=1 -x
56K     ./tmp
4.0K    ./lib64
8.0K    ./media
245M    ./lib
36M     ./srv
12M     ./sbin
2.5G    ./usr
4.0K    ./mnt
8.3M    ./etc
4.0K    ./opt
23M     ./root
9.5M    ./bin
16K     ./lost+found
422M    ./var
35M     ./boot
3.3G    .