vnd(4) [netbsd man page]

VND(4)							   BSD Kernel Interfaces Manual 						    VND(4)

NAME

     vnd -- vnode disk driver

SYNOPSIS

     pseudo-device vnd
     options VND_COMPRESSION

DESCRIPTION

     The vnd driver provides a disk-like interface to a file.  This is useful for a variety of applications, including swap files and building
     miniroot or floppy disk images.

     This document assumes that you're familiar with how to generate kernels, how to properly configure disks and pseudo-devices in a kernel con-
     figuration file.

     In order to compile in support for the vnd, you must add a line similar to the following to your kernel configuration file:

	   pseudo-device  vnd	    # vnode disk driver

     To also compile in support for reading compressed disk images, add the following option to your kernel config file:

	   options	  VND_COMPRESSION    # compressed vnd(4)

     Compressed disk images are expected in the cloop2 format, they can be created from "normal" disk images by the vndcompress(1) program.

     There is a run-time utility that is used for configuring both compressed and uncompressed vnds.  See vnconfig(8) for more information.

FILES

     /dev/{,r}vnd*  vnd device special files.

SEE ALSO

     config(1), vndcompress(1), MAKEDEV(8), fsck(8), mount(8), newfs(8), vnconfig(8)

HISTORY

     The vnode disk driver was originally written at the University of Utah.  The compression handling is based on code by Cliff Wright
     <cliff@snipe444.org>.

BUGS

     The vnd driver does not work if the file does not reside in a local filesystem.

     The vnd driver does not work if the file is sparse.

BSD
								 December 18, 2009							       BSD

VNDCOMPRESS(1)						    BSD General Commands Manual 					    VNDCOMPRESS(1)

NAME

     vndcompress, vnduncompress -- compress/uncompress file system images to/from cloop2 format

SYNOPSIS

     vndcompress [-cd] disk/fs-image compressed-image [blocksize]
     vnduncompress [-cd] compressed-image disk/fs-image

DESCRIPTION

     The vndcompress program compresses an existing file system image into a cloop2 compatible compressed file system image.  An optional block-
     size can be given.  If omitted, the default of 64kB is used.

     The vnduncompress command decompress a cloop2-compressed file system image back into a regular image.

     The file system images that can be handled are not limited to any specific file system, i.e. it is possible to handle images e.g. in ISO 9660
     or UFS/FFS format.  File system images in the cloop2 format are intended to be used with the vnd(4) driver in compressed mode as configured
     by the -z option of the vnconfig(8) program, and later mounted with the appropriate -t option to mount(8).

OPTIONS

     The following options are available:

     -c      Always compress, even if the program was started as vnduncompress.

     -d      Always uncompress (decompress), even if the program was started as vndcompress.

EXIT STATUS

     The vndcompress and vnduncompress utilities exit with one of the following values:

     0	   The operation was performed successfully.

     1	   An error occurred.

EXAMPLES

     To compress an existing CD-ROM file system image, run the following commands:

	   # vndcompress netbsd.iso netbsd.izo

     Note that the resulting compressed image cannot be mounted directly via NetBSD's vnd(4) and mount_cd9660(8) commands any longer.  Instead,
     you will have to use the -z option of vnconfig(8).

     The following example decompresses an existing CD-ROM file system image that was compressed in the cloop2 format into a regular file that can
     then be mounted:

	   # vnconfig vnd0 KNOPPIX.iso
	   # mount -t cd9660 -o ro /dev/vnd0d /mnt
	   # vnduncompress /mnt/KNOPPIX/KNOPPIX /var/tmp/knoppix.iso
	   # umount /mnt
	   # vnconfig -u vnd0
	   #
	   # vnconfig vnd1 /var/tmp/knoppix.iso
	   # mount -t cd9660 -o ro /dev/vnd1d /mnt
	   # ls /mnt
	   .rr_moved cdrom     floppy	 lib	   opt	     sbin      usr
	   bin	     dev       home	 mnt	   proc      sys       var
	   boot      etc       initrd	 none	   root      tmp       vmlinuz
	   # umount /mnt
	   # vnconfig -u vnd1

     As an alternative, if your vnd(4) was compiled with VND_COMPRESSION, you can use vnconfig(8) to access the cloop-compressed image directly,
     e.g.,

	   # vnconfig vnd0 KNOPPIX.iso
	   # mount -t cd9660 -o ro /dev/vnd0d /mnt
	   # vnconfig -z vnd1 /mnt/KNOPPIX/KNOPPIX
	   # mount -t cd9660 -o ro /dev/vnd1d /mnt2
	   # ls /mnt2
	   .rr_moved cdrom     floppy	 lib	   opt	     sbin      usr
	   bin	     dev       home	 mnt	   proc      sys       var
	   boot      etc       initrd	 none	   root      tmp       vmlinuz
	   # df /mnt /mnt2
	   Filesystem	 Size	   Used     Avail Capacity  Mounted on
	   /dev/vnd0a	 692M	  692M	      0B   100%    /mnt
	   /dev/vnd1a	 1.9G	  1.9G	      0B   100%    /mnt2
	   # umount /mnt2
	   # vnconfig -u vnd1
	   # umount /mnt
	   # vnconfig -u vnd0

     Note how the 1.9GB big filesystem on /mnt2 is mounted from the compressed file stored on the 692MB CD mounted on /mnt.  To create a com-
     pressed file system image of an existing directory and mount it, run:

	   # makefs -t ffs include.fs /usr/include
	   # vndcompress include.fs include.fs.cloop2
	   # vnconfig -z vnd0 include.fs.cloop2
	   # mount -o ro /dev/vnd0a /mnt
	   # ls /mnt

     To undo the steps, run:

	   # umount /mnt
	   # vnconfig -u vnd0
	   # rm /tmp/include.fs.cloop2
	   # rm /tmp/include.fs

SEE ALSO

     gzip(1), vnd(4), mount(8), mount_cd9660(8), vnconfig(8)

AUTHORS

     The vndcompress utility was written by Florian Stoehr <netbsd@wolfnode.de>.  The vndcompress manual page was written by Florian Stoehr
     <netbsd@wolfnode.de> and Hubert Feyrer <hubertf@NetBSD.org>.

BSD
								 December 12, 2005							       BSD