# df -h --total
Filesystem      Size  Used Avail Use% Mounted on
udev            984M     0  984M   0% /dev
tmpfs           200M  2.9M  197M   2% /run
/dev/sda        2.0G  1.7G  141M  93% /
tmpfs           998M     0  998M   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           998M     0  998M   0% /sys/fs/cgroup
tmpfs           200M     0  200M   0% /run/user/0
total           5.3G  1.7G  3.5G  33% -