.\" Copyright (C) 1998 Wolfgang Solfrank.
.\" Copyright (C) 1998 TooLs GmbH.
.\" All rights reserved.
.\"
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.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by TooLs GmbH.
.\" 4. The name of TooLs GmbH may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission.
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.\"	$NetBSD: mbrlabel.8,v 1.20 2013/02/27 21:21:47 wiz Exp $
.\"
.Dd February 27, 2013
.Dt MBRLABEL 8
.Os
.Sh NAME
.Nm mbrlabel
.Nd update disk label from MBR label(s)
.Sh SYNOPSIS
.Nm
.Op Fl fqrw
.Op Fl s Ar sector
.Ar device
.Sh DESCRIPTION
.Nm
is used to update a
.Nx
disk label from the Master Boot Record (MBR) label and Extended
Boot Record (EBR) label(s) found
on disks that were previously used on DOS/Windows systems (or
other MBR using systems).
.Pp
.Nm
scans the MBR contained in the very first block of the disk (or the
block specified through the
.Fl s
flag), then walks through every extended partition found and generates
additional partition entries for the disk from the EBRs found in
those extended partitions.
.Pp
Each MBR and each EBR partition which does not have an equivalent partition
in the disk label (equivalent in having the same size and offset) is added to
the first free partition slot in the disk label.
A free partition slot is defined as one with an
.Dv fstype
of
.Sq Li unused
and a
.Dv size
of zero
.Pq Sq 0 .
If there are not enough free slots in the disk label, a warning
will be issued.
.Pp
The raw partition (typically partition
.Em c ,
but
.Em d
on i386 and some other platforms) is left alone during this process.
.Pp
By default, the proposed changed disk label will be displayed and no
disk label update will occur.
.Pp
The following options are available:
.Bl -tag -width sXsectorX
.It Fl f
Force an update, even if there has been no change.
.It Fl q
Performs operations in a quiet fashion.
.It Fl r
In conjunction with
.Fl w ,
also update the on-disk label.
.It Fl s Ar sector
Specifies the logical sector number that has to be read from the disk
in order to find the MBR.
Useful if the disk has remapping drivers on it and the MBR is located
in a non-standard place.
Defaults to 0.
.It Fl w
Update the in-core label if it has been changed.
See also
.Fl r .
.El
.Sh SEE ALSO
.Xr disklabel 8 ,
.Xr dkctl 8 ,
.Xr fdisk 8 ,
.Xr mbr 8
.Rs
.%A Tn Microsoft corporation
.%T "Disk Concepts and Troubleshooting"
.%R Tn Microsoft technical library
.Re
.Sh HISTORY
The
.Nm
command appeared in
.Nx 1.4 .