freebsd-dev/usr.sbin/vnconfig/vnconfig.8
Julian Elischer a5296b05b4 Submitted by: Matt Dillon <dillon@freebsd.org>
The old VN device broke in -4.x when the definition of B_PAGING
changed. This patch fixes this plus implements additional capabilities.
The new VN device can be backed by a file ( as per normal ), or it can
be directly backed by swap.

Due to dependencies in VM include files  (on opt_xxx options) the new
vn device cannot be a module yet. This will be fixed in a later commit.
This commit delimitted by tags {PRE,POST}_MATT_VNDEV
1999-03-14 09:20:01 +00:00

212 lines
5.7 KiB
Groff

.\" Copyright (c) 1993 University of Utah.
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.\" @(#)vnconfig.8 8.1 (Berkeley) 6/5/93
.\"
.Dd July 8, 1993
.Dt VNCONFIG 8
.Os BSD 4
.Sh NAME
.Nm vnconfig
.Nd configure and enable vnode disks
.Sh SYNOPSIS
.Nm vnconfig
.Op Fl cdeguv
.Op Fl s Ar option
.Op Fl r Ar option
.Op Fl S Ar value
.Ar special_file Ar [regular_file]
.Op Ar feature
.Nm vnconfig
.Fl a
.Op Fl cdeguv
.Op Fl s Ar option
.Op Fl r Ar option
.Op Fl f Ar config_file
.Sh DESCRIPTION
The
.Nm
command configures and enables vnode pseudo disk devices.
The first form of the command will associate the special file
.Ar special_file
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. If you
want to use swap backing store for your device instead of a file, you
can leave regular_file out and specify the size of the block device
with the -S option.
.Pp
Options indicate an action to be performed:
.Bl -tag -width indent
.It Fl a
Read a command file and performs the
specified actions for each device/file pair.
.It Fl c
Configure the device.
If successful, references to
.Ar special_file
will access the contents of
.Ar regular_file .
.It Fl d
Disable (if possible) the specified feature.
.It Fl e
Configure the device and enables any
.Ar feature
that was specified.
If no feature was specified,
.Fl e
is the same as
.Fl c .
.It Fl f Ar config_file
Use
.Ar config_file
as an alternate config file.
.It Fl g
Fiddle global options.
.It Fl r Ar flag
Reset
.Ar flag .
The list of allowed flags and their meanings are:
.Bl -tag -width "follow"
.It Ar labels
use disk/slice labels.
.It Ar follow
debug flow in the
.Xr vn 4
driver.
.It Ar debug
debug data in the
.Xr vn 4
driver.
.It Ar io
debug I/O in the
.Xr vn 4
driver.
.It Ar all
turn on all flags.
.It Ar none
turn off all flags.
.El
.It Fl s Ar flag
Set
.Ar flag .
The list of allowed flags and their meanings are the same as for the
.Fl r
option.
.It Fl S Ar value{k,m,g,t}
If no regular file is specified, VN will use swap for backing store.
This option specifies the size of the device. For example, '23m' for
23 megabytes. The VN device will round the size up to a machine page boundry.
Filesystems up to 7.9 terrabytes are supported.
.It Fl u
Disable and ``unconfigure'' the device.
.It Fl v
Print messages to stdout describing actions taken.
.El
.Pp
If no action option is given,
.Fl c
is assumed.
.Pp
The
.Ar feature
argument specifies a feature that can be enabled via the
.Fl e
option:
.Bl -tag -width indent
.It Dv swap
Swapping is enabled on the special file.
See
.Xr swapon 2 .
.It Dv Pf mountro= Pa mount_point
The special file is mounted read-only on
.Ar mount_point .
See
.Xr mount 2 .
.It Dv Pf mountrw= Pa mount_point
The special file is mounted read-write on
.Ar mount_point .
See
.Xr mount 2 .
.It Dv Pf mount= Pa mount_point
Same as ``mountrw=''.
.El
.Pp
A configuration file contains one line per device/file pair in the form:
.Bd -literal
special_file regular_file [ feature ]
.Ed
.Pp
where fields are seperated by white space.
The previously described action options serve to configure, enable,
disable or unconfigure all devices in the configuration file.
.Sh FILES
.Bl -tag -width /etc/vntab -compact
.It Pa /etc/vntab
default configuration file for
.Fl a
option.
.El
.Sh EXAMPLES
.Pp
.Dl vnconfig /dev/vn0c /tmp/diskimage
.Pp
Configures the vnode disk
.Pa vn0c .
.Pp
.Dl vnconfig -e /dev/vn0c /var/swapfile swap
.Pp
Configures
.Pa vn0c
and enables swapping on it.
.Pp
.Dl vnconfig -d /dev/vn0c myfilesystem mount=/mnt
.Pp
Unmounts (disables)
.Pa vn0c .
.Pp
.Dl vnconfig -ae
.Pp
Configures and enables all devices specified in
.Pa /etc/vntab .
.Sh SEE ALSO
.Xr mount 2 ,
.Xr swapon 2 ,
.Xr unmount 2 ,
.Xr vn 4 .