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df(1) General Commands Manual df(1) NAME df - Displays statistics on free disk space SYNOPSIS [DIGITAL] 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 XPG4 behavior, set the CMD_ENV envi- ronment variable to xpg4. In this case, the df command uses the fol- lowing 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 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: XPG4, XPG4-UNIX Refer to the standards(5) reference page for more information about in- dustry standards and associated tags. OPTIONS Displays information about the mounted file systems, including the au- tomount intercept point. [DIGITAL] Displays statistics for the speci- fied file system type only. If the no prefix is used, all file sys- tems, except the one specified, are displayed. See the -t option de- scription for a list of available file system types. [DIGITAL] Re- ports the number of free inodes. The number of inodes controls the number of files that can exist in a file system. Causes the numbers to be reported in kilobytes. By default, all reported BSD compatible num- bers are in 512-byte blocks. [DIGITAL] Displays the previously ob- tained 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 exam- ple, 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 sta- tistics from the file systems; for some remote file systems, the sta- tistics displayed may be too obsolete to be useful. Produces output that consists of one line of information for each specified file sys- tem, with reported numbers in 512-byte blocks (default). Includes to- tal allocated space figures in the output (default). [DIGITAL (SVR4 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: [DIG- ITAL] UNIX File System (Berkeley fast file system) or a swap partition [DIGITAL] Network File System (NFS), Version 2 protocol [DIGI- TAL] Memory File System (RAM Disk) (See mfs(8)) [DIGITAL] PC File System [DIGITAL] System V File System [DIGITAL] ISO 9660 or High Sierra Formatted (CD-ROM) File System [DIGITAL] DCE Distributed File System [DIGITAL] DCE Episode File System [DIGITAL] Process File Sys- tem (used by debuggers) [DIGITAL] Advanced File System (AdvFS) [DIGI- TAL] File on File mount (used by streams) [DIGITAL] File Descriptor File System (used by streams) [DIGITAL] Reserved for third-party file systems [DIGITAL] Network File System, Version 3 protocol OPERANDS The name of a file, or file system, about which information is so- licited. If no value is specified, information is written on all mounted file systems. DESCRIPTION [DIGITAL] To obtain XPG4 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. [DIGITAL] 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). However, system administrators may specify either less or more reserved space for use by root. System V Compatibility [DIGITAL] 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. [DIGITAL] 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 [DIGITAL] For AdvFS file systems, the df command displays disk space usage information for each fileset. Because AdvFS uses a different de- sign than UFS, the df command reflects disk space usage somewhat dif- ferently than UFS. [DIGITAL] 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. [DIGITAL] AdvFS allows quotas to be established for filesets. Fileset quotas limit the amount of space that one fileset can use. For file- sets 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. [DIGITAL] The following is an explanation of each of the fields in the df command display for AdvFS file systems: [DIGITAL] The complete fileset name. The syntax is domain_name#fileset_name. [DIGITAL] 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. [DIGITAL] When fileset quotas are imposed, this field repre- sents the limit set by the fileset quota. [DIGITAL] The total amount of space used by the fileset. [DIGITAL] 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. [DIGITAL] When fileset quotas are established, this value re- flects the amount of space remaining until the quota limit is reached. If there is less available space in the domain than al- lowed by the quota limit, the available domain space is dis- played. [DIGITAL] How full the fileset is, represented as a percentage. This amount is calculated as: used/(used+avail- able). 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. [DIGITAL] The mount point of the file- set. The Blocks amount will never be the sum of the used and available fig- ures, since it includes metadata that is not included in either of the other two figures. The amount of space used for metadata can be com- puted as metadata = Blocks - (used + available) but this figure has no validity beyond an accounting curiosity. The available amount reflects space available for allocation of new files and the metadata for these files. The amount of space used for this metadata can not be pre- dicted, since it is dependent on the way the space is allocated (file, directory, or some other usage). RESTRICTIONS [DIGITAL] 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 er- ror occurred. ENVIRONMENT VARIABLES The following environment variables affect the execution of df: [DIGI- TAL] This variable must be set to xpg4 to cause the df command to ex- hibit XPG4 behavior. Provides a default value for the international- ization 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 in- ternationalization 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 lo- cale 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) Routines: getvfsbyname(3) Files: fs(4), fstab(4) Standards: standards(5) df(1)