df - Displays statistics on free disk space
[Tru64 UNIX] The default behavior for the df command is BSD SVR4 compli-
ant. 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 fol-
df [-eiknPt] [-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
Refer to the standards(5) reference page for more information about indus-
try standards and associated tags.
-e Displays information about the mounted file systems, including the
automount intercept point.
-F [no] fstype
[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.
-i [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.
-k Causes the numbers to be reported in kilobytes. By default, all
reported BSD compatible numbers are in 512-byte blocks.
-n [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.
-P Produces output that consists of one line of information for each
specified file system, with reported numbers in 512-byte blocks
-t Includes total allocated space figures in the output (default).
-t [no] fstype
[Tru64 UNIX] (SVR4 environment only) Displays statistics for only the
specified file system type. If the no prefix is used, all file sys-
tems, except the one specified, are displayed. Available file system
types include the following:
ufs [Tru64 UNIX] UNIX File System (Berkeley fast file system) or a
nfs [Tru64 UNIX] Network File System (NFS), Version 2 protocol
mfs [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 Sys-
dfs [Tru64 UNIX] DCE Distributed File System
efs [Tru64 UNIX] DCE Episode File System
[Tru64 UNIX] Process File System (used by debuggers)
[Tru64 UNIX] Advanced File System (AdvFS)
ffm [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
file | file_system
The name of a file, or file system, about which information is soli-
If no value is specified, information is written on all mounted file
[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
[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
.profile. The file /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 sys-
tem 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
[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 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 con-
strained 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 avail-
able 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
[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
[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 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 avail-
able 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, sym-
links, 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
[Tru64 UNIX] Reports the number of inodes in use in the fileset,
represented as a percentage. This amount is calculated as:
[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 character.
The following exit values are returned:
0 Successful completion.
>>0 An error occurred.
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 mes-
sages written to standard error.
Determines the location of message catalogues for the processing of
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)