How to use the df command in Linux

df (abbreviation for disk free) is a standard Unix command used to display the amount of available disk space for file systems on which the invoking user has appropriate read access. df is typically implemented using the statfs or statvfs system calls.

df (GNU coreutils) 8.22
Copyright (C) 2013 Free Software Foundation, Inc.

The df command provides an option to display sizes in Human Readable formats by using '-h' (prints the results in human readable format (e.g., 1K 2M 3G)).

Filesystem     Type      Size  Used Avail Use% Mounted on
/dev/vda1      ext4       50G   17G   31G  35% /
devtmpfs       devtmpfs  485M     0  485M   0% /dev

The syntax for the df command is as follows:

Usage: 
  ls [OPTION]... [FILE]...

OPTIONS:
-a, --all
include pseudo, duplicate, inaccessible file systems
-B, --block-size=SIZE
scale sizes by SIZE before printing them; e.g., '-BM' prints sizes in units of 1,048,576 bytes; see SIZE format below
--direct
show statistics for a file instead of mount point
--total
produce a grand total
-h, --human-readable
print sizes in human readable format (e.g., 1K 234M 2G)
-H, --si
likewise, but use powers of 1000 not 1024
-i, --inodes
list inode information instead of block usage
-k
like --block-size=1K
-l, --local
limit listing to local file systems
--no-sync
do not invoke sync before getting usage info (default)
--output[=FIELD_LIST]
use the output format defined by FIELD_LIST, or print all fields if FIELD_LIST is omitted.
-P, --portability
use the POSIX output format
--sync
invoke sync before getting usage info
-t, --type=TYPE
limit listing to file systems of type TYPE
-T, --print-type
print file system type
-x, --exclude-type=TYPE
limit listing to file systems not of type TYPE
-v
(ignored)
--help
display this help and exit
--version
output version information and exit

Display values are in units of the first available SIZE from --block-size, and the DF_BLOCK_SIZE, BLOCK_SIZE and BLOCKSIZE environment variables. Otherwise, units default to 1024 bytes (or 512 if POSIXLY_CORRECT is set).

SIZE is an integer and optional unit (example: 10M is 10*1024*1024). Units are K, M, G, T, P, E, Z, Y (powers of 1024) or KB, MB, ... (powers of 1000).

FIELD_LIST is a comma-separated list of columns to be included. Valid field names are: 'source', 'fstype', 'itotal', 'iused', 'iavail', 'ipcent', 'size', 'used', 'avail', 'pcent', 'file' and 'target' (see info page).