1 .\" Copyright (c) 1993 University of Utah.
2 .\" Copyright (c) 1980, 1989, 1991, 1993
3 .\" The Regents of the University of California. All rights reserved.
5 .\" Poul-Henning Kamp All rights reserved.
7 .\" This code is derived from software contributed to Berkeley by
8 .\" the Systems Programming Group of the University of Utah Computer
9 .\" Science Department.
11 .\" Redistribution and use in source and binary forms, with or without
12 .\" modification, are permitted provided that the following conditions
14 .\" 1. Redistributions of source code must retain the above copyright
15 .\" notice, this list of conditions and the following disclaimer.
16 .\" 2. Redistributions in binary form must reproduce the above copyright
17 .\" notice, this list of conditions and the following disclaimer in the
18 .\" documentation and/or other materials provided with the distribution.
19 .\" 3. All advertising materials mentioning features or use of this software
20 .\" must display the following acknowledgement:
21 .\" This product includes software developed by the University of
22 .\" California, Berkeley and its contributors.
23 .\" 4. Neither the name of the University nor the names of its contributors
24 .\" may be used to endorse or promote products derived from this software
25 .\" without specific prior written permission.
27 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 .\" @(#)vnconfig.8 8.1 (Berkeley) 6/5/93
40 .\" from: src/usr.sbin/vnconfig/vnconfig.8,v 1.19 2000/12/27 15:30:29
49 .Nd configure and enable memory disks
55 .Oo Fl o Oo Cm no Oc Ns Ar option Oc ...
58 .Op Fl S Ar sectorsize
60 .Op Fl x Ar sectors/track
72 utility configures and enables
76 Options indicate an action to be performed:
77 .Bl -tag -width indent
80 This will configure and attach a memory disk with the
81 parameters specified and attach it to the system.
83 Detach a memory disk from the system and release all resources.
85 Select the type of the memory disk.
86 .Bl -tag -width "preload"
88 Storage for this type of memory disk is allocated with
90 This limits the size to the malloc bucket limit in the kernel.
93 option is not set, creating and filling a large
94 malloc-backed memory disk is a very easy way to
99 becomes the backingstore for this memory disk.
101 Swap space is used to back this memory disk.
104 Filename to use for the vnode type memory disk. Options
108 are implied if not specified.
110 List configured devices.
113 display details about that particular device.
115 When printing md device names, print only the unit number without the
118 Size of the memory disk.
120 is the number of 512 byte sectors unless suffixed with a
125 denotes byte, kilobyte, megabyte, gigabyte and terabyte respectively. Options
129 are implied if not specified.
130 .It Fl S Ar sectorsize
131 Sectorsize to use for malloc backed device.
132 .It Fl x Ar sectors/track
133 See the description of the
136 .It Fl y Ar heads/cylinder
145 options can be used to specify a synthetic geometry.
146 This is useful for constructing bootable images for later download to
148 .It Fl o Oo Cm no Oc Ns Ar option
149 Set or reset options.
150 .Bl -tag -width indent
151 .It Oo Cm no Oc Ns Cm async
154 backed devices: avoid
156 for increased performance but
157 at the risk of deadlocking the entire kernel.
158 .It Oo Cm no Oc Ns Cm reserve
159 Allocate and reserve all needed storage from the start, rather than as needed.
160 .It Oo Cm no Oc Ns Cm cluster
161 Enable clustering on this disk.
162 .It Oo Cm no Oc Ns Cm compress
163 Enable/Disable compression features to reduce memory usage.
164 .It Oo Cm no Oc Ns Cm force
165 Disable/Enable extra sanity checks to prevent the user from doing something
166 that might adversely affect the system.
167 .It Oo Cm no Oc Ns Cm readonly
168 Enable/Disable readonly mode.
171 Request a specific unit number for the
173 device instead of automatic allocation.
176 To create a 4 megabyte
179 The name of the allocated unit will be output on stdout like
182 .Dl mdconfig -a -t malloc -s 4m
184 To create a disk named
190 .Dl mdconfig -a -t vnode -f /tmp/boot.flp -u 4
192 To detach and free all resources used by
197 To create and mount a 128MByte swap backed file system on
199 .Bd -literal -offset indent
200 mdconfig -a -t swap -s 128M -u 10
206 To create a 5MB file-backed disk (
211 .Bd -literal -offset indent
212 dd if=/dev/zero of=somebackingfile bs=1k count=5k
213 mdconfig -f somebackingfile -u 0
219 To mount an ISO 9660 CD image file:
220 .Bd -literal -offset indent
221 mdconfig -a -t vnode -u 10 -f cdimage.iso
222 mount_cd9660 /dev/md10 /mnt
233 utility first appeared in
235 as a cleaner replacement for the
243 utility was written by
244 .An Poul-Henning Kamp
245 .Aq phk@FreeBSD.org .