md(4) [netbsd man page]

MD(4)							   BSD Kernel Interfaces Manual 						     MD(4)

NAME

     md -- memory disk driver

SYNOPSIS

     pseudo-device md [count]

DESCRIPTION

     The md driver enables use of system or user memory as a disk.  Memory for the disk must be allocated within the kernel or with mdconfig(8)
     before the md device may be used as a disk.  Its behaviour is configured by the kernel options MEMORY_DISK_HOOKS, MEMORY_DISK_IS_ROOT,
     MEMORY_DISK_ROOT_SIZE, MEMORY_DISK_DYNAMIC, and MEMORY_DISK_SERVER.

FILES

     /dev/md??	 block mode memory disk devices.
     /dev/rmd??  raw mode memory disk devices.

SEE ALSO

     options(4), mdconfig(8), mdsetimage(8)

BSD
								 February 25, 2007							       BSD

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