1.\" Copyright (c) 1987, 1988, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" Symmetric Computer Systems. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. All advertising materials mentioning features or use of this software 16.\" must display the following acknowledgement: 17.\" This product includes software developed by the University of 18.\" California, Berkeley and its contributors. 19.\" 4. Neither the name of the University nor the names of its contributors 20.\" may be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33.\" SUCH DAMAGE. 34.\" 35.\" @(#)disklabel.8 8.2 (Berkeley) 4/19/94 36.\" 37.Dd "April 19, 1994" 38.Dt DISKLABEL 8 39.Os BSD 4.2 40.Sh NAME 41.Nm disklabel 42.Nd read and write disk pack label 43.Sh SYNOPSIS 44.Nm disklabel 45.Op Fl r 46.Ar disk 47.Nm disklabel 48.Fl w 49.Op Fl r 50.Ar disk Ar disktype 51.Oo Ar packid Oc 52.Nm disklabel 53.Fl e 54.Op Fl r 55.Ar disk 56.Nm disklabel 57.Fl R 58.Op Fl r 59.Ar disk Ar protofile 60.Nm disklabel 61.Op Fl NW 62.Ar disk 63.sp 64.Nm disklabel 65.Fl B 66.Oo 67.Fl b Ar boot1 68.Op Fl s Ar boot2 69.Oc 70.Ar disk 71.Oo Ar disktype Oc 72.Nm disklabel 73.Fl w 74.Fl B 75.Oo 76.Fl b Ar boot1 77.Op Fl s Ar boot2 78.Oc 79.Ar disk Ar disktype 80.Oo Ar packid Oc 81.Nm disklabel 82.Fl R 83.Fl B 84.Oo 85.Fl b Ar boot1 86.Op Fl s Ar boot2 87.Oc 88.Ar disk Ar protofile 89.Oo Ar disktype Oc 90.Sh DESCRIPTION 91.Nm Disklabel 92can be used to install, examine or modify the label on a disk drive or pack. 93When writing the label, it can be used 94to change the drive identification, 95the disk partitions on the drive, 96or to replace a damaged label. 97On some systems, 98.Nm disklabel 99can be used to install bootstrap code as well. 100There are several forms of the command that read (display), install or edit 101the label on a disk. 102Each form has an additional option, 103.Fl r , 104which causes the label to be read from or written to the disk directly, 105rather than going through the system's in-core copy of the label. 106This option may allow a label to be installed on a disk 107without kernel support for a label, such as when labels are first installed 108on a system; it must be used when first installing a label on a disk. 109The specific effect of 110.Fl r 111is described under each command. 112The read and install forms also support the 113.Fl B 114option to install bootstrap code. 115These variants are described later. 116.Pp 117The first form of the command (read) is used to examine the label on the named 118disk drive (e.g. sd0 or /dev/rsd0c). 119It will display all of the parameters associated with the drive 120and its partition layout. 121Unless the 122.Fl r 123flag is given, 124the kernel's in-core copy of the label is displayed; 125if the disk has no label, or the partition types on the disk are incorrect, 126the kernel may have constructed or modified the label. 127If the 128.Fl r 129flag is given, the label from the raw disk will be displayed rather 130than the in-core label. 131.Pp 132The second form of the command, with the 133.Fl w 134flag, is used to write a standard label on the designated drive. 135The required arguments to 136.Nm disklabel 137are the drive to be labelled (e.g. sd0), and 138the drive type as described in the 139.Xr disktab 5 140file. 141The drive parameters and partitions are taken from that file. 142If different disks of the same physical type are to have different 143partitions, it will be necessary to have separate disktab entries 144describing each, or to edit the label after installation as described below. 145The optional argument is a pack identification string, 146up to 16 characters long. 147The pack id must be quoted if it contains blanks. 148If the 149.Fl r 150flag is given, the disk sectors containing the label and bootstrap 151will be written directly. 152A side-effect of this is that any existing bootstrap code will be overwritten 153and the disk rendered unbootable. 154If 155.Fl r 156is not specified, 157the existing label will be updated via the in-core copy and any bootstrap 158code will be unaffected. 159If the disk does not already have a label, the 160.Fl r 161flag must be used. 162In either case, the kernel's in-core label is replaced. 163.Pp 164An existing disk label may be edited by using the 165.Fl e 166flag. 167The label is read from the in-core kernel copy, 168or directly from the disk if the 169.Fl r 170flag is also given. 171The label is formatted and then supplied to an editor for changes. 172If no editor is specified in an 173.Ev EDITOR 174environment variable, 175.Xr vi 1 176is used. 177When the editor terminates, the formatted label is reread 178and used to rewrite the disk label. 179Existing bootstrap code is unchanged regardless of whether 180.Fl r 181was specified. 182.Pp 183With the 184.Fl R 185flag, 186.Nm disklabel 187is capable of restoring a disk label that was formatted 188in a prior operation and saved in an ascii file. 189The prototype file used to create the label should be in the same format 190as that produced when reading or editing a label. 191Comments are delimited by 192.Ar \&# 193and newline. 194As with 195.Fl w , 196any existing bootstrap code will be clobbered if 197.Fl r 198is specified and will be unaffected otherwise. 199.Pp 200The 201.Fl NW 202flags for 203.Nm disklabel 204explicitly disallow and 205allow, respectively, writing of the pack label area on the selected disk. 206.Pp 207The final three forms of 208.Nm disklabel 209are used to install boostrap code on machines where the bootstrap is part 210of the label. 211The bootstrap code is comprised of one or two boot programs depending on 212the machine. 213The 214.Fl B 215option is used to denote that bootstrap code is to be installed. 216The 217.Fl r 218flag is implied by 219.Fl B 220and never needs to be specified. 221The name of the boot program(s) to be installed can be selected in a 222variety of ways. 223First, the names can be specified explicitly via the 224.Fl b 225and 226.Fl s 227flags. 228On machines with only a single level of boot program, 229.Fl b 230is the name of that program. 231For machines with a two-level bootstrap, 232.Fl b 233indicates the primary boot program and 234.Fl s 235the secondary boot program. 236If the names are not explicitly given, standard boot programs will be used. 237The boot programs are located in 238.Pa /usr/mdec . 239The names of the programs are taken from the ``b0'' and ``b1'' parameters 240of the 241.Xr disktab 5 242entry for the disk if 243.Ar disktype 244was given and its disktab entry exists and includes those parameters. 245Otherwise, boot program names are derived from the name of the disk. 246These names are of the form 247.Pa basename Ns boot 248for the primary (or only) bootstrap, and 249.Pf boot Pa basename 250for the secondary bootstrap; 251for example, 252.Pa /usr/mdec/sdboot 253and 254.Pa /usr/mdec/bootsd 255if the disk device is 256.Em sd0 . 257.Pp 258The first of the three boot-installation forms is used to install 259bootstrap code without changing the existing label. 260It is essentially a read command with respect to the disk label 261itself and all options are related to the specification of the boot 262program as described previously. 263The final two forms are analogous to the basic write and restore versions 264except that they will install bootstrap code in addition to a new label. 265.Sh FILES 266.Bl -tag -width Pa -compact 267.It Pa /etc/disktab 268.It Pa /usr/mdec/ Ns Em xx Ns boot 269.It Pa /usr/mdec/boot Ns Em xx 270.El 271.Sh EXAMPLES 272.Dl disklabel sd0 273.Pp 274Display the in-core label for sd0 as obtained via 275.Pa /dev/rsd0c . 276.Pp 277.Dl disklabel -w -r /dev/rsd0c sd2212 foo 278.Pp 279Create a label for sd0 based on information for ``sd2212'' found in 280.Pa /etc/disktab . 281Any existing bootstrap code will be clobbered. 282.Pp 283.Dl disklabel -e -r sd0 284.Pp 285Read the on-disk label for sd0, edit it and reinstall in-core as well 286as on-disk. 287Existing bootstrap code is unaffected. 288.Pp 289.Dl disklabel -R sd0 mylabel 290.Pp 291Restore the on-disk and in-core label for sd0 from information in 292.Pa mylabel . 293Existing bootstrap code is unaffected. 294.Pp 295.Dl disklabel -B sd0 296.Pp 297Install a new bootstrap on sd0. 298The boot code comes from 299.Pa /usr/mdec/sdboot 300and possibly 301.Pa /usr/mdec/bootsd . 302On-disk and in-core labels are unchanged. 303.Pp 304.Dl disklabel -w -B /dev/rsd0c -b newboot sd2212 305.Pp 306Install a new label and bootstrap. 307The label is derived from disktab information for ``sd2212'' and 308installed both in-core and on-disk. 309The bootstrap code comes from the file 310.Pa /usr/mdec/newboot . 311.Sh SEE ALSO 312.Xr disktab 5 , 313.Xr disklabel 5 314.Sh DIAGNOSTICS 315The kernel device drivers will not allow the size of a disk partition 316to be decreased or the offset of a partition to be changed while it is open. 317Some device drivers create a label containing only a single large partition 318if a disk is unlabeled; thus, the label must be written to the ``a'' 319partition of the disk while it is open. 320This sometimes requires the desired label to be set in two steps, 321the first one creating at least one other partition, 322and the second setting the label on the new partition 323while shrinking the ``a'' partition. 324.Pp 325On some machines the bootstrap code may not fit entirely in the area 326allocated for it by some filesystems. 327As a result, it may not be possible to have filesystems on some partitions 328of a ``bootable'' disk. 329When installing bootstrap code, 330.Nm disklabel 331checks for these cases. 332If the installed boot code would overlap a partition of type FS_UNUSED 333it is marked as type FS_BOOT. 334The 335.Xr newfs 8 336utility will disallow creation of filesystems on FS_BOOT partitions. 337Conversely, if a partition has a type other than FS_UNUSED or FS_BOOT, 338.Nm disklabel 339will not install bootstrap code that overlaps it. 340.Sh BUGS 341When a disk name is given without a full pathname, 342the constructed device name uses the ``a'' partition on the tahoe, 343the ``c'' partition on all others. 344