df: Report filesystem disk space usage
df reports the amount of disk space used and available on
With no arguments,
df reports the space used and available on all
currently mounted filesystems (of all types). Otherwise,
reports on the filesystem containing each argument file.
Normally the disk space is printed in units of
1024 bytes, but this can be overridden (see section 2.2 Block size).
Non-integer quantities are rounded up to the next higher unit.
If an argument file is a disk device file containing a mounted
df shows the space available on that filesystem
rather than on the filesystem containing the device node (i.e., the root
df does not attempt to determine the disk usage
on unmounted filesystems, because on most kinds of systems doing so
requires extremely nonportable intimate knowledge of filesystem
The program accepts the following options. Also see 2. Common options.
Include in the listing filesystems that have a size of 0 blocks, which
are omitted by default. Such filesystems are typically special-purpose
pseudo-filesystems, such as automounter entries. Also, filesystems of
type "ignore" or "auto", supported by some operating systems, are
only included if this option is specified.
- `-B size'
Scale sizes by size before printing them (see section 2.2 Block size).
For example, `-BG' prints sizes in units of 1,073,741,824 bytes.
Append a size letter to each size, such as `M' for mebibytes.
Powers of 1024 are used, not 1000; `M' stands for 1,048,576 bytes.
Use the `-H' or `--si' option if you prefer powers of 1000.
Append an SI-style abbreviation to each size, such as `MB' for
megabytes. Powers of 1000 are used, not 1024; `MB' stands for
1,000,000 bytes. Use the `-h' or `--human-readable' option if
you prefer powers of 1024.
List inode usage information instead of block usage. An inode (short
for index node) contains information about a file such as its owner,
permissions, timestamps, and location on the disk.
Print sizes in 1024-byte blocks, overriding the default block size
(see section 2.2 Block size).
This option is equivalent to `--block-size=1K'.
Limit the listing to local filesystems. By default, remote filesystems
are also listed.
Do not invoke the
sync system call before getting any usage data.
This may make
df run significantly faster on systems with many
disks, but on some systems (notably SunOS) the results may be slightly
out of date. This is the default.
Use the POSIX output format. This is like the default format except
for the following:
The information about each filesystem is always printed on exactly
one line; a mount device is never put on a line by itself. This means
that if the mount device name is more than 20 characters long (e.g., for
some network mounts), the columns are misaligned.
The labels in the header output line are changed to conform to POSIX.
sync system call before getting any usage data. On
some systems (notably SunOS), doing this yields more up to date results,
but in general this option makes
df much slower, especially when
there are many or very busy filesystems.
- `-t fstype'
Limit the listing to filesystems of type fstype. Multiple
filesystem types can be specified by giving multiple `-t' options.
By default, nothing is omitted.
Print each filesystem's type. The types printed here are the same ones
you can include or exclude with `-t' and `-x'. The particular
types printed are whatever is supported by the system. Here are some of
the common names (this list is certainly not exhaustive):
An NFS filesystem, i.e., one mounted over a network from another
machine. This is the one type name which seems to be used uniformly by
- `4.2, ufs, efs...'
A filesystem on a locally-mounted hard disk. (The system might even
support more than one type here; Linux does.)
- `hsfs, cdfs'
A filesystem on a CD-ROM drive. HP-UX uses `cdfs', most other
systems use `hsfs' (`hs' for "High Sierra").
An MS-DOS filesystem, usually on a diskette.
- `-x fstype'
Limit the listing to filesystems not of type fstype.
Multiple filesystem types can be eliminated by giving multiple
`-x' options. By default, no filesystem types are omitted.
- Ignored; for compatibility with System V versions of