.\"	$OpenBSD: vnconfig.8,v 1.16 2001/11/08 11:20:47 mpech Exp $
.\"
.\" Copyright (c) 1993 University of Utah.
.\" Copyright (c) 1980, 1989, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" the Systems Programming Group of the University of Utah Computer
.\" Science Department.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
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.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
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.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
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.\"     @(#)vnconfig.8	8.1 (Berkeley) 6/5/93
.\"
.Dd July 8, 1993
.Dt VNCONFIG 8
.Os
.Sh NAME
.Nm vnconfig
.Nd "configure vnode disks for file swapping or pseudo file systems"
.Sh SYNOPSIS
.Nm vnconfig
.Op Fl c
.Op Fl vk
.Ar rawdev
.Ar regular_file
.Nm vnconfig Fl u
.Op Fl v
.Ar rawdev
.Sh DESCRIPTION
The
.Nm
command configures vnode pseudo disk devices.
It will associate (or disassociate) the special file
.Ar rawdev
with the regular file
.Ar regular_file
allowing the latter to be accessed as though it were a disk.
Hence a regular file within the filesystem can be used for swapping
or can contain a filesystem that is mounted in the name space.
Both traditional devices,
.Pa vnd ,
and the cache-coherent devices,
.Pa svnd ,
are configured through
.Nm vnconfig .
.Pp
If you read the regular file while using
.Pa svnd ,
you need to mount the
.Pa svnd
with the mount option
.Ar sync
to ensure consistency in the buffer cache.
For normal operation this is not necessary.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl c
Configures the device.
If successful, references to
.Ar rawdev
will access the contents of
.Ar regular_file .
This is the default operation.
.It Fl k
Associate an encryption key with the device.
All data will be encrypted before it is written to the disk.
Encryption only works with 
.Pa svnd .
.It Fl u
Unconfigures the device.
.It Fl v
Print messages to stdout describing actions taken.
.El
.Pp
If no action option is given,
.Fl c
is assumed.
.Sh FILES
.Bl -tag -width /etc/rvnd?? -compact
.It Pa /dev/{,r}{,s}vnd*
.El
.Sh EXAMPLES
Configure the vnode disk
.Pa svnd0
(all of its partitions become usable):
.Pp
.Dl vnconfig svnd0 /tmp/diskimage
.Pp
Unconfigure the same device:
.Pp
.Dl vnconfig -u svnd0
.Sh BUGS
This command should really be named
.Nm vndconfig .
.Sh SEE ALSO
.Xr vnd 4 ,
.Xr mount 8 ,
.Xr swapon 8 ,
.Xr umount 8