NAME

df − report free disk space on file systems (includes NFS extensions)

SYNOPSIS

df [ −i ] [ filesystem ... ] [ file ... ]

DESCRIPTION

Df prints out the amount of free disk space available on the specified filesystem, e.g. “/dev/rp0a”, or on the filesystem in which the specified file, e.g. “$HOME”, is contained.  If no file system is specified, the free space on all of the normally mounted file systems is printed.  The reported numbers are in kilobytes.  Df reports on NFS file systems that are mounted; it does not report on AFS file systems. 

NFS

In NFS, df displays the amount of disk space occupied by currently mounted file systems, the amount of used and available space, and how much of the file system’s total capacity has been used.  Used without arguments, df reports on all mounted file systems.  For example, df will produce:

FilesystemkbytesusedavailcapacityMounted on
/dev/hd0a 7445 4714198670%/
/dev/hd0g4227735291275893%/usr

Note that used+avail is less than the amount of space in the file system (kbytes); this is because the system reserves a fraction of the space in the file system to allow its file system allocation routines to work well.  The amount reserved is typically about 10%; this may be adjusted using tunefs. When all the space on a file system except for this reserve is in use, only the super-user can allocate new files and data blocks to existing files.  When a file system is overallocated in this way, df may report that the file system is more than 100% utilized. 

If arguments to df are disk partitions (for example, /dev/hd0a) or UNIX path names, df produces a report on the file system containing the named file. Thus "df ." shows the amount of space on the file system containing the current directory. 

In NFS, df displays remotely mounted files as "server_name:path_on_server" instead of their device name.  For example, df will produce:

FilesystemkbytesusedavailcapacityMounted on
perch:/usr4296135385542787%/usr
perch:/usr/src4277736868377091%/usr/source

OPTIONS

−i Report also the number of inodes which are used and free. 

BUGS

When the −i option is used, remotely mounted file systems give values of iused = 0, ifree = -1, and %iused = 0 because they are never set.  See statfs(2) for more detail. 

FILES

/etc/fstablist of normally mounted filesystems
/etc/mtablist of currently mounted filesystems

SEE ALSO

fstab(5), icheck(8), quot(8), du(1V), mtab(5), tunefs(8), statfs(2)

PRPQs 5799-WZQ/5799-PFF: IBM/4.3  —  Sept 1988