How to check free space in Ubuntu

To check free space in Ubuntu (or other Linux systems) we have an easy command df (disk filesystem)

If we execute the command directly without any flag we get an output like:

>> df
 
Filesystem      1K-blocks      Used  Available Use% Mounted on
/dev/sdb3        76766240  42579596   30264008  59% /
none                    4         0          4   0% /sys/fs/cgroup
udev              2491912         4    2491908   1% /dev
tmpfs              507956      1672     506284   1% /run
none                 5120         0       5120   0% /run/lock
none              2539780     85684    2454096   4% /run/shm
none               102400        68     102332   1% /run/user
/dev/sda5      1622761776 298717540 1241589608  20% /media/USERNAME/EXTERNAL-HDD
/dev/sdc1         7812864   4940784    2872080  64% /media/USERNAME/USB

To get a readable result of the command we can add the flag '-h':

>> df -h
 
Filesystem      Size  Used Avail Use% Mounted on
/dev/sdb3        74G   41G   29G  59% /
none            4,0K     0  4,0K   0% /sys/fs/cgroup
udev            2,4G  4,0K  2,4G   1% /dev
tmpfs           497M  1,7M  495M   1% /run
none            5,0M     0  5,0M   0% /run/lock
none            2,5G   84M  2,4G   4% /run/shm
none            100M   68K  100M   1% /run/user
/dev/sda5       1,6T  285G  1,2T  20% /media/USERNAME/EXTERNAL-HDD
/dev/sdc1       7,5G  4,8G  2,8G  64% /media/USERNAME/USB

Other interesting flags:

• 'df -m': Show space in MB
• 'df -hT /home': Show folder '/home' information
• 'df -i': Show inode information
• 'df -T': Show the type of the file system