To view disk usage via cli.
$ df -h --total
Example Output:
Filesystem Size Used Avail Use% Mounted on
udev 992M 0 992M 0% /dev
tmpfs 201M 23M 178M 12% /run
/dev/vda7 50G 39G 8.6G 82% /
tmpfs 1003M 0 1003M 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 1003M 0 1003M 0% /sys/fs/cgroup
tmpfs 201M 0 201M 0% /run/user/1003
tmpfs 201M 0 201M 0% /run/user/1001
total 53G 39G 13G 77% -