df(1)df(1)NAMEdf - Displays statistics on free disk space
SYNOPSIS
[Tru64 UNIX] The default behavior for the df command is BSD SVR4 com‐
pliant. In this case, the df command uses the following syntax: df
[-ehiknP] [-t fstype] [file | file_system...]
To cause the df command to exhibit XCU5.0 behavior, set the CMD_ENV
environment variable to xpg4. In this case, the df command uses the
following syntax: df [-ehiknPt] [-F fstype] [file | file_system...]
Note
The CMD_ENV environment variable also affects the behavior of the echo
command. The BIN_SH environment variable affects the XPG4 compliance
of the Bourne shell.
The df command displays statistics on the amount of free disk space on
file_system or on the file system that contains the specified file.
STANDARDS
Interfaces documented on this reference page conform to industry stan‐
dards as follows:
df: XCU5.0
Refer to the standards(5) reference page for more information about
industry standards and associated tags.
OPTIONS
Displays information about the mounted file systems, including the
automount intercept point. [Tru64 UNIX] Displays statistics for the
specified file system type only. If the no prefix is used, all file
systems, except the one specified, are displayed. See the -t option
description for a list of available file system types. [Tru64
UNIX] Causes the numbers to be scaled and reported in a human readable
form. By default, all reported BSD compatible numbers are in 512-byte
blocks. This can be confusing when the sizes of disks are always talked
about in megabytes and gigabutes, so 400 (512-byte blocks) will appear
as 200K (200 kilobytes) and 21138064 (512-byte blocks) will be reported
as 10G (10 gigabytes), and so on. The suffixes used are K (kilobyte),
M (megabyte), G (gigabyte), T (terabyte), P (petabyte), and E
(exabyte). [Tru64 UNIX] Reports the number of free and used inodes.
The number of inodes controls the number of files that can exist in a
file system. [Tru64 UNIX] The total amount of space in the file
domain Causes the numbers to be reported in kilobytes. By default, all
reported BSD compatible numbers are in 512-byte blocks. [Tru64
UNIX] Displays the previously obtained statistics from all mounted
file systems. Use this option if it is possible that one or more file
systems are in a state such that they will not be able to provide sta‐
tistics without a long delay (for example, if you have a remote file
system on a server that has crashed). If you specify the -n option,
the df command does not request new statistics from the file systems;
for some remote file systems, the statistics displayed may be too obso‐
lete to be useful. Produces output that consists of one line of infor‐
mation for each specified file system, with reported numbers in
512-byte blocks (default). Includes total allocated space figures in
the output (default). [Tru64 UNIX] (SVR4 environment only) Displays
statistics for only the specified file system type. If the no prefix
is used, all file systems, except the one specified, are displayed.
Available file system types include the following: [Tru64 UNIX] UNIX
File System (Berkeley fast file system) or a swap partition [Tru64
UNIX] Network File System (NFS), Version 2 protocol [Tru64 UNIX] Mem‐
ory File System (RAM Disk) (See mfs(8)) [Tru64 UNIX] PC File System
[Tru64 UNIX] System V File System [Tru64 UNIX] ISO 9660 or High
Sierra Formatted (CD-ROM) File System [Tru64 UNIX] DCE Distributed
File System [Tru64 UNIX] DCE Episode File System [Tru64 UNIX] Process
File System (used by debuggers) [Tru64 UNIX] Advanced File System
(AdvFS) [Tru64 UNIX] File on File mount (used by streams) [Tru64
UNIX] File Descriptor File System (used by streams) [Tru64
UNIX] Reserved for third-party file systems [Tru64 UNIX] Network File
System, Version 3 protocol
OPERANDS
The name of a file, or file system, about which information is
solicited.
If no value is specified, information is written on all mounted
file systems.
DESCRIPTION
[Tru64 UNIX] To obtain XCU5.0 compliance, set the environment variable
CMD_ENV to xpg4. If the environment variable is not set or it is set
to another value, the environment defaults to BSD SVR4. If neither a
file or a file system is specified, statistics for all mounted file
systems are displayed.
[Tru64 UNIX] When file system disk usage exceeds 100% of the allowed
space for users, the df command displays a negative number of free
blocks. The allowed space for users is typically 90% of disk capacity,
with 10% reserved for use by root only (this is not true for AdvFS, see
below). Consequently as a result of this, the disk usage is under
reported by approximately 10%. However, system administrators may spec‐
ify either less or more reserved space for use by root.
System V Compatibility
[Tru64 UNIX] The root of the directory tree that contains the commands
modified for SVID 2 compliance is specified in the file
/etc/svid2_path. You can use /etc/svid2_profile as the basis for, or to
include in, your /etc/svid2_profile reads /etc/svid2_path and sets the
first entries in the PATH environment variable so that the modified
SVID 2 commands are found first.
[Tru64 UNIX] The df command, as modified for SVID 2 compliance,
accepts one command line option (-t, print space totals) and an
optional file system name or device name. The command displays the
mount point, the mounted device, the number of free blocks (in 512-byte
quantities), and the number of free inodes. If the -t option is speci‐
fied, the command displays, on a separate line following the free block
counts, the total number of blocks and inodes for each mounted device.
Advanced File System
[Tru64 UNIX] For AdvFS file systems, the df command displays disk
space usage information for each fileset. Because AdvFS uses a differ‐
ent design than UFS, the df command reflects disk space usage somewhat
differently than UFS.
[Tru64 UNIX] AdvFS uses a domain-fileset model rather than a one-file
system-per-volume model like traditional UNIX file systems. A fileset
can reside alone on a single-volume domain (a UFS model), alone on a
multi-volume domain, or can share a single or multi-volume domain with
other filesets. A fileset can consume all space in its domain or it
may be constrained by fileset quotas.
[Tru64 UNIX] AdvFS allows quotas to be established for filesets. File‐
set quotas limit the amount of space that one fileset can use. For
filesets that have quotas established, the 512-blocks, Avail, and
Capacity values reflect limits imposed by quotas. They do not represent
actual space available in the file domain unless there is less space in
the domain than allowed by the quota limit. When both soft and hard
limits are set, the lower limit is used to calculate totals.
[Tru64 UNIX] The following is an explanation of each of the fields in
the df command display for AdvFS file systems: [Tru64 UNIX] The com‐
plete fileset name. The syntax is domain_name#fileset_name. [Tru64
UNIX] The total amount of space in the file domain in which the file‐
set resides, represented in either 512K blocks or 1024K blocks. Meta‐
data, which takes away space from the domain and is not available for
filesets to use, is included as reserved in this total. This total rep‐
resents: used+free+reserved.
[Tru64 UNIX] When fileset quotas are imposed, this field repre‐
sents the limit set by the fileset quota. [Tru64 UNIX] The
total amount of space in the file domain in which the fileset
resides, represented in either K (kilobyte), M (megabyte), G
(gigabyte), T (terabyte), P (petabyte), and E (exabyte) scaled
values. [Tru64 UNIX] The total amount of space used by the
fileset. When run against an AdvFS fileset clone, the number
reported for Used blocks is the number of blocks used in the
original fileset at the time the clone fileset was created.
[Tru64 UNIX] The total amount of unused space in the domain
available to the fileset. Because ALL unused space in the file
domain is available to all of the filesets, this value is the
same for all filesets in a domain, unless fileset quotas are
established.
[Tru64 UNIX] When fileset quotas are established, this value
reflects the amount of space remaining until the quota limit is
reached. If there is less available space in the domain than
allowed by the quota limit, the available domain space is dis‐
played. [Tru64 UNIX] How full the fileset is, represented as a
percentage. This amount is calculated as: used/(used+available).
In domains with multiple filesets, the total capacity of all
filesets in that domain can be greater than 100%. This is
because the available space value used in the calculation is
available to all of the filesets; each fileset capacity is cal‐
culated independently. [Tru64 UNIX] Reports the number of
inodes in use by normal files, symlinks, and all directories in
the fileset. When run against an AdvFS clone, Iused reports the
number of inodes in use by the original fileset at the time the
clone fileset was created. [Tru64 UNIX] Reports the total num‐
ber of inodes available for use in the fileset. [Tru64
UNIX] Reports the number of inodes in use in the fileset, rep‐
resented as a percentage. This amount is calculated as:
Iused/(Iused+Ifree). [Tru64 UNIX] The mount point of the file‐
set.On a TruCluster Server, showfsets can sometimes report
incorrect disk usage. Data in CFS client caches is synchronized
to the server at least every 30 seconds. Incorrect disk usage is
reported if stale data exists in client caches when the showf‐
sets executes.
[Tru64 UNIX] Note
On a TruCluster Server, df can sometimes report incorrect disk
usage. Data in CFS client caches is synchronized to the server
at least every 30 seconds. The disk usage reported does not
account for dirty data in client caches that has not yet been
synchronized to the server.
RESTRICTIONS
[Tru64 UNIX] The df command supports mount point pathnames of up to
MNAMELEN, which includes the null terminating character.
EXIT STATUS
The following exit values are returned: Successful completion. An
error occurred.
ENVIRONMENT VARIABLES
The following environment variables affect the execution of df: [Tru64
UNIX] This variable must be set to xpg4 to cause the df command to
exhibit XCU5.0 behavior. Provides a default value for the internation‐
alization variables that are unset or null. If LANG is unset or null,
the corresponding value from the default locale is used. If any of the
internationalization variables contain an invalid setting, the utility
behaves as if none of the variables had been defined. If set to a non-
empty string value, overrides the values of all the other internation‐
alization variables. Determines the locale for the interpretation of
sequences of bytes of text data as characters (for example, single-byte
as opposed to multi-byte characters in arguments). Determines the
locale for the format and contents of diagnostic messages written to
standard error. Determines the location of message catalogues for the
processing of LC_MESSAGES.
SEE ALSO
Commands: du(1), echo(1), find(1), ksh(1), mount(8), quot(8),
quota(1), Bourne shell sh(1b), POSIX shell sh(1p), showfdmn(8), showf‐
sets(8)
Functions: fstatfs(2), mount(2), statfs(2), statvfs(2)
Routines: getvfsbyname(3)
Files: fs(4), fstab(4)
Standards: standards(5)df(1)