DF(1)

NAME
df - display free disk space

SYNOPSIS
df [-b | -g | -H | -h | -k | -m | -P] [-acilnT] [-], [-t type] [file | filesystem ...]

DESCRIPTION
The df utility displays statistics about the amount of free disk space on the specified mounted file system or on the file system of which file is a part. By default block counts are displayed with an assumed block size of 512 bytes. If neither a file or a file system operand is specified, statistics for all mounted file systems are displayed (subject to the -t option below).

The following options are available:

-a  Accepted for command-line compatibility. Linux does not expose a direct equivalent of FreeBSD's MNT_IGNORE mount flag in /proc/self/mountinfo, so this option has no additional effect in this port.

-b  Explicitly use 512 byte blocks, overriding any BLOCKSIZE specification from the environment. This is the same as the -P option. The -k option overrides this option.

-c  Display a grand total.

-g  Use 1073741824 byte (1 Gibibyte) blocks rather than the default. This overrides any BLOCKSIZE specification from the environment.

-h  “Human-readable” output. Use unit suffixes: Byte, Kibibyte, Mebibyte, Gibibyte, Tebibyte and Pebibyte (based on powers of 1024) in order to reduce the number of digits to four or fewer.

-H, - -si
    Same as -h but based on powers of 1000.

-i  Include statistics on the number of free and used inodes. In conjunction with the -h or -H options, the number of inodes is scaled by powers of 1000. In case the filesystem has no inodes then ‘-’ is displayed instead of the usage percentage.

-k  Use 1024 byte (1 Kibibyte) blocks rather than the default. This overrides the -P option and any BLOCKSIZE specification from the environment.

-l  Select a locally-mounted file system for display. If used in combination with the -t type option, file system types will be added or excluded according to the parameters of that option. This Linux port classifies remote file systems by mount type, the “_netdev” mount option, and remote-style sources such as “host:/path” or “//server/share”.

-m  Use 1048576 byte (1 Mebibyte) blocks rather than the default. This overrides any BLOCKSIZE specification from the environment.

-n  This flag is recognized but rejected on Linux. The standalone Linux port reads mount metadata from /proc/self/mountinfo and refreshes filesystem counters with statvfs(3) for each selected mountpoint, and Linux does not provide an equivalent cached-statistics mode for this utility.

-P  Explicitly use 512 byte blocks, overriding any BLOCKSIZE specification from the environment. This is the same as the -b option. The -k option overrides this option.

-t type
    Select file systems to display. More than one type may be specified in a comma separated list. The list of file system types can be prefixed with “no” to specify the file system types for which action should not be taken. If used in combination with the -l option, the parameters of this option will modify the list of locally-mounted file systems selected by the -l option. For example, the df command:

        df -t nonfs,nullfs

    lists all file systems except those of type NFS and NULLFS. On Linux, mounted filesystem types can be inspected via /proc/self/mountinfo.

-T  Include file system type.

-,  (Comma) Print sizes grouped and separated by thousands using the non-monetary separator returned by localeconv(3), typically a comma or period. If no locale is set, or the locale does not have a non-monetary separator, this option has no effect.

ENVIRONMENT

BLOCKSIZE
    Specifies the units in which to report block counts. This Linux port accepts units of bytes or numbers scaled with the letters k (for multiples of 1024 bytes), m (for multiples of 1048576 bytes) or g (for gibibytes). The allowed range is 512 bytes to 1 GB. If the value is outside, it will be set to the appropriate limit.

EXAMPLES
Show human readable free disk space for all mount points including file system type:

    $ df -ahT
    Filesystem   Type        Size    Used   Avail Capacity  Mounted on
    /dev/ada1p2  ufs         213G    152G     44G    78%    /
    devfs        devfs       1.0K    1.0K      0B   100%    /dev
    /dev/ada0p1  ufs         1.8T    168G    1.5T    10%    /data
    linsysfs     linsysfs    4.0K    4.0K      0B   100%    /compat/linux/sys
    /dev/da0     msdosfs     7.6G    424M    7.2G     5%    /mnt/usb

Show inode statistics except for devfs or linsysfs file systems. Note that the “no” prefix affects all the file systems in the list and the -t option can be specified only once:

    $ df -i -t nodevfs,linsysfs
    Filesystem   1K-blocks      Used      Avail Capacity iused     ifree %iused
    Mounted on
    /dev/ada1p2  223235736 159618992   45757888    78% 1657590  27234568    6%   /
    /dev/ada0p1 1892163184 176319420 1564470712    10% 1319710 243300576    1%
    /data
    /dev/da0       7989888    433664    7556224     5%       0         0  100%
    /mnt/usb

Show human readable information for the file system containing the file /etc/rc.conf:

    $ df -h /etc/rc.conf
    Filesystem     Size    Used   Avail Capacity  Mounted on
    /dev/ada1p2    213G    152G     44G    78%    /

Same as above but specifying some file system:

    $ df -h /dev/ada1p2
    Filesystem     Size    Used   Avail Capacity  Mounted on
    /dev/ada1p2    213G    152G     44G    78%    /

NOTES
For non-Unix file systems, the reported values of used and free inodes may have a different meaning than that of used and available files and directories. An example is msdosfs, which in the case of FAT12 or FAT16 file systems reports the number of available and free root directory entries instead of inodes ( where 1 to 21 such directory entries are required to store each file or directory name or disk label).

SEE ALSO
lsvfs(1), quota(1), fstatfs(2), statfs(2), statvfs(3), localeconv(3), fstab(5), mount(8), pstat(8), quot(8), swapinfo(8)

STANDARDS
With the exception of most options, the df utility conforms to p1003.1-2004, which defines only the -k, -P and -t options.

HISTORY
A df command appeared in AT&T UNIX.

BUGS
The -n flag is ignored if a file or file system is specified. Also, if a mount point is not accessible by the user, it is possible that the file system information could be stale.

The -b and -P options are identical. The former comes from the BSD tradition, and the latter is required for p1003.1-2004 conformity.