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LOSETUP(8)		     MAINTENANCE COMMANDS		    LOSETUP(8)

NAME
       losetup - set up	and control loop devices

SYNOPSIS
       losetup [ -e encryption ] [ -o offset ] loop_device file
       losetup [ -d ] loop_device

DESCRIPTION
       losetup	is  used to associate loop devices with	regular	files or block
       devices,	to detach loop devices and to query the	status of a  loop  de-
       vice. If	only the loop_device argument is given,	the status of the cor-
       responding loop device is shown.

OPTIONS
       -d     detach the file or device	associated with	the specified loop de-
	      vice.

       -e encryption
	      enable data encryption. The following keywords are recognized:

	      NONE   use no encryption (default).
	      XOR    use a simple XOR encryption.
	      DES    use  DES  encryption. DES encryption is only available if
		     the optional DES package has been added  to  the  kernel.
		     DES  encryption  uses  an	additional start value that is
		     used to protect passwords against dictionary attacks.

       -o offset
	      the data start is	moved offset bytes into	the specified file  or
	      device.

RETURN VALUE
       losetup returns 0 on success, nonzero on	failure. When losetup displays
       the status of a loop device, it returns 1 if the	device is not  config-
       ured  and 2 if an error occurred	which prevented	losetup	from determin-
       ing the status of the device.

FILES
       /dev/loop0,/dev/loop1,...   loop	devices	(major=7)

EXAMPLE
       If you are using	the loadable module you	must have  the	module	loaded
       first with the command

	      #	insmod loop.o

       The  following commands can be used as an example of using the loop de-
       vice.

	      dd if=/dev/zero of=/file bs=1k count=100
	      losetup -e des /dev/loop0	/file
	      Password:
	      Init (up to 16 hex digits):
	      mkfs -t ext2 /dev/loop0 100
	      mount -t ext2 /dev/loop0 /mnt
	       ...
	      umount /dev/loop0
	      losetup -d /dev/loop0

       If you are using	the loadable module you	may remove the module with the
       command

	      #	rmmod loop

RESTRICTION
       DES  encryption	is  painfully slow. On the other hand, XOR is terribly
       weak.

AUTHORS
       Original	version: Theodore Ts'o <tytso@athena.mit.edu>
       Original	DES by:	Eric Young <eay@psych.psy.uq.oz.au>

Linux				  Nov 24 1993			    LOSETUP(8)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | RETURN VALUE | FILES | EXAMPLE | RESTRICTION | AUTHORS

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