df - Displays statistics on free disk space
[Tru64 UNIX] The default behavior for the df command is
BSD SVR4 compliant. In this case, the df command uses the
following syntax: df [-ehiknP] [-t fstype] [file |
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...]
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.
Interfaces documented on this reference page conform to
industry standards as follows:
Refer to the standards(5) reference page for more information
about industry standards and associated tags.
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 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
The name of a file, or file system, about which information
If no value is specified, information is written on
all mounted file systems.
[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 [Toc] [Back]
[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 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 [Toc] [Back]
[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
[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 singlevolume
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:
[Tru64 UNIX] When fileset quotas are imposed, this
field represents 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 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] 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 number of inodes
available for use in the fileset. [Tru64
UNIX] Reports the number of inodes in use in the
fileset, represented as a percentage. This amount
is calculated as: Iused/(Iused+Ifree). [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.
[Tru64 UNIX] The df command supports mount point pathnames
of up to MNAMELEN, which includes the null terminating
The following exit values are returned: Successful completion.
An error occurred.
ENVIRONMENT VARIABLES [Toc] [Back]
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 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 internationalization
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
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)
Files: fs(4), fstab(4)
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