df(1) General Commands Manual df(1)
NAME
df - Displays statistics on free disk space
SYNOPSIS
[Tru64 UNIX] The default behavior for the df command is BSD SVR4 compliant. In this case, the df command uses the following syntax: df
[-eiknP] [-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 [-eiknPt] [-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 compli-
ance 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 standards 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] Reports the number of free inodes. The number of inodes controls the
number of files that can exist in a file system. Reports Iused for AdvFS clone filesets as the number of files in use by the original file-
set at the time the clone fileset was created. 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 statistics 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 obsolete to be useful.
Produces output that consists of one line of information 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] Memory 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
specify 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 quanti-
ties), and the number of free inodes. If the -t option is specified, 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 different
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 file-
set 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. Fileset 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
complete fileset name. The syntax is domain_name#fileset_name. [Tru64 UNIX] The total amount of space in the file domain in which the
fileset resides, represented in either 512K blocks or 1024K blocks. Metadata, which takes away space from the domain and is not available
for filesets to use, is included as reserved in this total. This total represents: used+free+reserved.
[Tru64 UNIX] When fileset quotas are imposed, this field represents the limit set by the fileset quota. [Tru64 UNIX] The total
amount of space used by the fileset. When run against an AdvFS clone fileset, 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 displayed.
[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 calculated independently. [Tru64
UNIX] The mount point of the fileset.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 showfsets 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 internationalization 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 util-
ity 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 inter-
nationalization 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), showfsets(8)
Functions: fstatfs(2), mount(2), statfs(2), statvfs(2)
Routines: getvfsbyname(3)
Files: fs(4), fstab(4)
Standards: standards(5)
df(1)