Most commands that are used in filesystem administration require that the filesystem type be provided on the command line or in the filesystem table. Most of these commands also attempt to distinguish the type of a filesystem by themselves, so if the administrator provides the wrong type the command might fail. It is important to specify the correct type because filesystems can be damaged if a command fails to detect an administrator's error and an operation applicable only to one type of filesystem is applied to another.
At times, an administrator will need to determine
the type of an unmounted filesystem
either because the
contains outdated information or because it contains
no information at all.
uses certain methods to determine
the type of an unmounted filesystem.
determines and displays the filesystem type on
If the type cannot be determined, the message
Unknown_fstyp (no matches)
appears as standard error output.