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 acknowledgment: 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.\" $FreeBSD$ 37.\" 38.Dd March 15, 2003 39.Dt BSDLABEL 8 40.Os 41.Sh NAME 42.Nm bsdlabel 43.Nd read and write disk pack label 44.Sh SYNOPSIS 45.Nm 46.Op Fl A 47.Ar disk 48.Nm 49.Fl w 50.Op Fl nA 51.Op Fl B Op Fl b Ar boot 52.Op Fl m Ar machine 53.Ar disk 54.Op Ar type 55.Nm 56.Fl e 57.Op Fl nA 58.Op Fl B Op Fl b Ar boot 59.Op Fl m Ar machine 60.Ar disk 61.Nm 62.Fl R 63.Op Fl nA 64.Op Fl B Op Fl b Ar boot 65.Op Fl m Ar machine 66.Ar disk protofile 67.Pp 68.Sh DESCRIPTION 69The 70.Nm 71utility 72installs, examines or modifies the BSD label on a disk partition. 73In addition, 74.Nm 75can install bootstrap code. 76.Ss Disk Device Name 77When specifying the device, 78the 79.Pa /dev/ 80path prefix may be omitted; 81the 82.Nm 83utility will automatically prepend it. 84.Ss General options 85The 86.Fl A 87option enables processing of the historical parts of the BSD label. 88If the option is not given, suitable values are set for these fields. 89.Pp 90The 91.Fl n 92stops the 93.Nm 94program right before the disk would have been modified, and displays 95the result instead of writing it. 96.Pp 97The 98.Fl m Ar machine 99argument instructs 100.Nm 101to use the layout suitable for the specified machine. 102.Ss Reading the Disk Label 103To examine the label on a disk drive, use 104.Nm 105without options: 106.Pp 107.Nm 108.Op Fl A 109.Op Fl m Ar machine 110.Ar disk 111.Pp 112.Ar disk 113represents the disk in question, and may be in the form 114.Pa da0 115or 116.Pa /dev/da0 . 117It will display the partition layout. 118.Ss Writing a Standard Label 119To write a standard label, use the form 120.Pp 121.Nm 122.Fl w 123.Op Fl nA 124.Op Fl m Ar machine 125.Ar disk 126.Op Ar type 127.Pp 128If the drive type if specified the entry of that name in the 129.Xr disktab 5 130file is used, otherwise a default layout is used. 131.Ss Editing an Existing Disk Label 132To edit an existing disk label, use the form 133.Pp 134.Nm 135.Fl e 136.Op Fl nA 137.Op Fl m Ar machine 138.Ar disk 139.Pp 140This command opens the disklabel in the default editor and when the editor 141exits the label is validated and if OK written to disk. 142.Ss Restoring a Disk Label From a File 143To restore a disk label from a file, use the form 144.Pp 145.Nm 146.Fl R 147.Op Fl nA 148.Op Fl m Ar machine 149.Ar disk protofile 150.Pp 151.Nm 152is capable of restoring a disk label that was previously saved in a file in 153.Tn ASCII 154format. 155The prototype file used to create the label should be in the same format as that 156produced when reading or editing a label. 157Comments are delimited by 158.Ql # 159and newline. 160.Ss Installing Bootstraps 161If the 162.Fl B 163argument is specified, bootstrap code will be read from the file 164.Pa /boot/boot 165and written to the disk. 166The 167.Fl b Ar boot 168argument allows a different file to be used. 169.Sh FILES 170.Bl -tag -width ".Pa /etc/disktab" -compact 171.It Pa /boot/boot 172Default boot image. 173.It Pa /etc/disktab 174Disk description file. 175.El 176.Sh SAVED FILE FORMAT 177The 178.Nm 179utility 180uses an 181.Tn ASCII 182version of the label when examining, editing, or restoring a disk 183label. 184The format is: 185.Bd -literal -offset 4n 186 1878 partitions: 188# size offset fstype [fsize bsize bps/cpg] 189 a: 81920 0 4.2BSD 1024 8192 16 190 b: 160000 81920 swap 191 c: 1173930 0 unused 0 0 # "raw" part, don't edit 192.Ed 193.Pp 194If the 195.Fl A 196option is specified, the format is: 197.Bd -literal -offset 4n 198# /dev/da1c: 199type: SCSI 200disk: da0s1 201label: 202flags: 203bytes/sector: 512 204sectors/track: 51 205tracks/cylinder: 19 206sectors/cylinder: 969 207cylinders: 1211 208sectors/unit: 1173930 209rpm: 3600 210interleave: 1 211trackskew: 0 212cylinderskew: 0 213headswitch: 0 # milliseconds 214track-to-track seek: 0 # milliseconds 215drivedata: 0 216 2178 partitions: 218# size offset fstype [fsize bsize bps/cpg] 219 a: 81920 0 4.2BSD 1024 8192 16 220 b: 160000 81920 swap 221 c: 1173930 0 unused 0 0 # "raw" part, don't edit 222.Ed 223.Pp 224Lines starting with a 225.Ql # 226mark are comments. 227.Pp 228The partition table can have up to 8 entries. 229It contains the following information: 230.Bl -tag -width indent 231.It Ar # 232The partition identifier is a single letter in the range 233.Ql a 234to 235.Ql h . 236By convention, partition 237.Ql c 238is reserved to describe the entire disk. 239.It Ar size 240The size of the partition in sectors, 241.Cm K 242(kilobytes - 1024), 243.Cm M 244(megabytes - 1024*1024), 245.Cm G 246(gigabytes - 1024*1024*1024), 247.Cm % 248(percentage of free space 249.Em after 250removing any fixed-size partitions other than partition 251.Ql c ) , 252or 253.Cm * 254(all remaining free space 255.Em after 256fixed-size and percentage partitions). 257For partition 258.Ql c , 259a size of 260.Cm * 261indicates the entire disk. 262Lowercase versions of 263.Cm K , M , 264and 265.Cm G 266are allowed. 267Size and type should be specifed without any spaces between them. 268.Pp 269Example: 2097152, 1G, 1024M and 1048576K are all the same size 270(assuming 512-byte sectors). 271.It Ar offset 272The offset of the start of the partition from the beginning of the 273drive in sectors, or 274.Cm * 275to have 276.Nm 277calculate the correct offset to use (the end of the previous partition plus 278one, ignoring partition 279.Ql c . 280For partition 281.Ql c , 282.Cm * 283will be interpreted as an offset of 0. 284.It Ar fstype 285Describes the purpose of the partition. 286The example shows all currently used partition types. 287For 288.Tn UFS 289file systems and 290.Xr ccd 4 291partitions, use type 292.Cm 4.2BSD . 293For Vinum drives, use type 294.Cm vinum . 295Other common types are 296.Cm swap 297and 298.Cm unused . 299By convention, partition 300.Ql c 301represents the entire slice and should be of type 302.Cm unused , 303though 304.Nm 305does not enforce this convention. 306The 307.Nm 308utility 309also knows about a number of other partition types, 310none of which are in current use. 311(See the definitions starting with 312.Dv FS_UNUSED 313in 314.Aq Pa sys/disklabel.h 315for more details.) 316.It Ar fsize 317For 318.Cm 4.2BSD 319and 320.Tn LFS 321file systems only, the fragment size. 322Defaults to 1024 for partitions smaller than 1GB, 3234096 for partitions 1GB or larger. 324.It Ar bsize 325For 326.Cm 4.2BSD 327and 328.Tn LFS 329file systems only, the block size. 330Defaults to 8192 for partitions smaller than 1GB, 33116384 for partitions 1GB or larger. 332.It Ar bps/cpg 333For 334.Cm 4.2BSD 335file systems, the number of cylinders in a cylinder group. 336For 337.Tn LFS 338file systems, the segment shift value. 339Defaults to 16 for partitions smaller than 1GB, 34064 for partitions 1GB or larger. 341.El 342.Sh EXAMPLES 343.Dl "bsdlabel da0s1" 344.Pp 345Display the label for the first slice of the 346.Pa da0 347disk, as obtained via 348.Pa /dev/da0s1 . 349.Pp 350.Dl "bsdlabel da0s1 > savedlabel" 351.Pp 352Save the in-core label for 353.Pa da0s1 354into the file 355.Pa savedlabel . 356This file can be used with the 357.Fl R 358option to restore the label at a later date. 359.Pp 360.Dl "bsdlabel -w /dev/da0s1" 361.Pp 362Create a label for 363.Pa da0s1 364.Pp 365.Dl "bsdlabel -e da0s1" 366.Pp 367Read the label for 368.Pa da0s1 , 369edit it, and install the result. 370.Pp 371.Dl "bsdlabel -e -n da0s1" 372.Pp 373Read the on-disk label for 374.Pa da0s1 , 375edit it, and display what the new label would be (in sectors). 376It does 377.Em not 378install the new label either in-core or on-disk. 379.Pp 380.Dl "bsdlabel -w da0s1" 381.Pp 382Write a default label on 383.Pa da0s1 . 384Use another 385.Nm Fl e 386command to edit the 387partitioning and file system information. 388.Pp 389.Dl "bsdlabel -R da0s1 savedlabel" 390.Pp 391Restore the on-disk and in-core label for 392.Pa da0s1 393from information in 394.Pa savedlabel . 395.Pp 396.Dl "bsdlabel -R -n da0s1 label_layout" 397.Pp 398Display what the label would be for 399.Pa da0s1 400using the partition layout in 401.Pa label_layout . 402This is useful for determining how much space would be alloted for various 403partitions with a labelling scheme using 404.Cm % Ns -based 405or 406.Cm * 407partition sizes. 408.Pp 409.Dl "bsdlabel -B da0s1" 410.Pp 411Install a new bootstrap on 412.Pa da0s1 . 413The boot code comes from 414.Pa /boot/boot . 415.Pp 416.Dl "bsdlabel -w -B -b newboot /dev/da0s1" 417.Pp 418Install a new label and bootstrap. 419The bootstrap code comes from the file 420.Pa newboot 421in the current working directory. 422.Bd -literal -offset indent 423dd if=/dev/zero of=/dev/da0 bs=512 count=32 424fdisk -BI da0 425dd if=/dev/zero of=/dev/da0s1 bs=512 count=32 426bsdlabel -w -B da0s1 427bsdlabel -e da0s1 428.Ed 429.Pp 430Completely wipe any prior information on the disk, creating a new bootable 431disk with a 432.Tn DOS 433partition table containing one slice, covering the whole disk. 434Initialize the label on this slice, 435then edit it. 436The 437.Xr dd 1 438commands are optional, but may be necessary for some 439.Tn BIOS Ns es 440to properly 441recognize the disk. 442.Pp 443This is an example disk label that uses some of the new partition size types 444such as 445.Cm % , M , G , 446and 447.Cm * , 448which could be used as a source file for 449.Dq Li "bsdlabel -R ad0s1c new_label_file" : 450.Bd -literal -offset 4n 451# /dev/ad0s1c: 452 4538 partitions: 454# size offset fstype [fsize bsize bps/cpg] 455 a: 400M 0 4.2BSD 4096 16384 75 # (Cyl. 0 - 812*) 456 b: 1G * swap 457 c: * * unused 458 e: 204800 * 4.2BSD 459 f: 5g * 4.2BSD 460 g: * * 4.2BSD 461.Ed 462.Sh SEE ALSO 463.Xr geom 4 , 464.Xr ccd 4 , 465.Xr md 4 , 466.Xr disklabel 5 , 467.Xr disktab 5 , 468.Xr boot0cfg 8 , 469.Xr fdisk 8 470.Sh DIAGNOSTICS 471The kernel device drivers will not allow the size of a disk partition 472to be decreased or the offset of a partition to be changed while it is open. 473