2.11BSD#431 - /usr/man/cat8/mount.0

MOUNT(8)	    UNIX Programmer's Manual		 MOUNT(8)


NAME
     mount - mount file systems

SYNOPSIS
     mount [ -adfruvw ] [ -t ufs | external_type ]
     mount [ -dfruvw ] special | node
     mount [ -dfruvw ] [ -o options ] [ -t ufs | external_type ]
     special node

DESCRIPTION
     The mount command calls the mount(2) system call to prepare
     and graft a special device on to the file system tree at the
     point node.  If either special or node are not provided, the
     appropriate information is taken from the fstab(5) file.

     The system maintains a list of currently mounted file sys-
     tems.  If no arguments are given to mount, this list is
     printed.

     The options are as follows:


     -a        Causes everything to be done except for the actual
	       system call.  This option is useful in conjunction
	       with the

     -v        flag to determine what the mount command is trying
	       to do.

     -f        Forces the revocation of write access when trying
	       to downgrade a filesystem mount status from read-
	       write to read-only.  For 2.11BSD this flag is
	       currently not implemented.

     -o        Options are specified with a -o flag followed by a
	       comma separated string of options.  The following
	       options are available:


	       async	 All I/O to the file system should be
			 done asynchronously.

			 This is a dangerous flag to and should
			 not be used unless system should your
			 system crash.

	       force	 The same as -f; forces the revocation of
			 write access when trying to downgrade a
			 filesystem mount status from read-write
			 to read-only.	 This is not (and likely
			 never will be) supported in 2.11BSD.


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MOUNT(8)	    UNIX Programmer's Manual		 MOUNT(8)


	       noaccesstime
			 File access times are not updated.

			 This is a performance optimization for
			 read-only, short-lived data, e.g., news.

	       noauto	 This filesystem should be skipped when
			 mount is run with the -a flag.

	       na	 Same as noauto.

	       nodev	 Do not interpret character or block spe-
			 cial devices on the file system.  This
			 option is useful for a server that has
			 file systems containing special devices
			 for architectures other than its own.

	       noexec	 Do not allow execution of any binaries
			 on the mounted file system.  This option
			 is useful for a server that has file
			 systems containing binaries for archi-
			 tectures other than its own.

	       nosuid	 Do not allow set-user-identifier or
			 set-group-identifier bits to take
			 effect.

	       rdonly	 The same as -r; mount the file system
			 read-only (even the super-user may not
			 write it).

	       sync	 All I/O to the file system should be
			 done synchronously.

	       update	 The same as -u; indicate that the status
			 of an already mounted file system should
			 be changed.

	       Any additional options specific to a filesystem
	       type that is not one of the internally known types
	       (see the -t option) may be passed as a comma
	       separated list; these options are distinguished by
	       a leading - (dash).  Options that take a value are
	       specified using the syntax -option=value.  At
	       present no 2.11BSD mount options use the following
	       form, the example has been retained for illustra-
	       tive purposes only.  For example, the mount com-
	       mand:

	       mount -t mfs -o nosuid,-N,-s=4000 /dev/dk0b /tmp


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MOUNT(8)	    UNIX Programmer's Manual		 MOUNT(8)


	       causes mount to execute the equivalent of:

	       /sbin/mount_mfs -o nosuid -N -s 4000 /dev/dk0b
	       /tmp

       -r	 The file system is to be mounted read-only.
		 Mount the file system read-only (even the
		 super-user may not write it).	The same as the
		 ``rdonly'' argument to the -o option.

       -t "ufs | external type"
		 The argument following the -t is used to indi-
		 cate the file system type.  The type ufs is the
		 default.  Ufs is also the only value supported
		 by 2.11BSD other than swap.  Thus the -t will
		 rarely be used.  The -t option can be used to
		 indicate that the actions should only be taken
		 on filesystems of the specified type.	More than
		 one type may be specified in a comma separated
		 list.	The list of filesystem types can be pre-
		 fixed with ``no'' to specify the filesystem
		 types for which action should not be taken.  For
		 example, the mount command:

		 mount -a -t nonfs,mfs

		 mounts all filesystems except those of type NFS
		 and MFS.

		 If the type is not one of the internally known
		 types, mount will attempt to execute a program
		 in /sbin/mount_XXX where XXX is replaced by the
		 type name.  For example, mfs filesystems are
		 mounted by the program /sbin/mount_mfs.

       -u	 The -u flag indicates that the status of an
		 already mounted file system should be changed.
		 Any of the options discussed above (the -o
		 option) may be changed; also a file system can
		 be changed from read-only to read-write or vice
		 versa.  An attempt to change from read-write to
		 read-only will fail if any files on the filesys-
		 tem are currently open for writing unless the -f
		 flag is also specified.  This is currently not
		 implemented in 2.11BSD.  The ability to change
		 the flags (nodev, nosuid, etc) is however sup-
		 ported.  The set of options is determined by
		 first extracting the options for the file system
		 from the fstab table, then applying any options
		 specified by the -o argument, and finally apply-
		 ing the -r or -w option.


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MOUNT(8)	    UNIX Programmer's Manual		 MOUNT(8)


       -v	 Verbose mode.

       -w	 The file system object is to be read and write.

FILES
     /etc/fstab
	       file system table

SEE ALSO
     mount(2), fstab(5), umount(8)

BUGS
     It is possible for a corrupted file system to cause a crash.

     mount and this manpage were ported from 4.4BSD-Lite to
     2.11BSD to gain the ability to set the various flags such as
     nodev, nosuid and so on.	Multiple filesystem types are not
     supported and several of the options and flags are not
     implemented.

HISTORY
     A mount command appeared in Version 6 AT&T UNIX.


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