The df command displays information about total space and available space on a file system. You can specify the name of a device on which the file system is located, the directory on which the file system is mounted, or the relative path name of the file system. You can also specify a file or directory that is not a mount point, and the df command displays information for the file system on which the file or directory is located. If you just specify the command with no parameters, it displays information for all currently mounted file systems. File system statistics are displayed in units of 512-byte blocks by default.
The df command gets file system space statistics from the statfs system call. However, when you specify the -s flag, you get the statistics from the virtual file system (VFS) specific file system helper. Under certain exceptional conditions, such as when a file system is being modified while the df command is running, the statistics displayed by the df command might not be accurate.
To display information about all mounted file systems, enter:
If your system has the
/, /usr, /site, and/usr/venus systems mounted, the output
from the df command resembles this:
Filesystem 512-blocks Free %Used Iused %Iused Mounted on /dev/hd0 19368 9976 48% 4714 5% / /dev/hd1 24212 4808 80% 5013 19% /usr /dev/hd2 9744 9352 4% 1900 4% /site /dev/hd3 3868 3856 0% 986 0% /usr/venus