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.\" 4. Neither the name of the University nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" @(#)disklabel.8 8.2 (Berkeley) 4/19/94 32.\" $FreeBSD$ 33.\" 34.Dd October 13, 2006 35.Dt BSDLABEL 8 36.Os 37.Sh NAME 38.Nm bsdlabel 39.Nd read and write BSD label 40.Sh SYNOPSIS 41.Nm 42.Op Fl A 43.Ar disk | Fl f Ar file 44.Nm 45.Fl w 46.Op Fl \&An 47.Op Fl B Op Fl b Ar boot 48.Op Fl m Ar machine 49.Ar disk | Fl f Ar file 50.Op Ar type 51.Nm 52.Fl e 53.Op Fl \&An 54.Op Fl B Op Fl b Ar boot 55.Op Fl m Ar machine 56.Ar disk | Fl f Ar file 57.Nm 58.Fl R 59.Op Fl \&An 60.Op Fl B Op Fl b Ar boot 61.Op Fl m Ar machine 62.Op Fl f 63.Ar disk | Fl f Ar file 64.Ar protofile 65.Sh DESCRIPTION 66The 67.Nm 68utility 69installs, examines or modifies the 70.Bx 71label on a disk partition, or on a file containing a partition image. 72In addition, 73.Nm 74can install bootstrap code. 75.Ss Disk Device Name 76When specifying the device (i.e., when the 77.Fl f 78option is not used), 79the 80.Pa /dev/ 81path prefix may be omitted; 82the 83.Nm 84utility will automatically prepend it. 85.Ss General Options 86The 87.Fl A 88option enables processing of the historical parts of the 89.Bx 90label. 91If the option is not given, suitable values are set for these fields. 92.Pp 93The 94.Fl f 95option tells 96.Nm 97that the program will operate on a file instead of a disk partition. 98.Pp 99The 100.Fl n 101option stops the 102.Nm 103program right before the disk would have been modified, and displays 104the result instead of writing it. 105.Pp 106The 107.Fl m Ar machine 108argument forces 109.Nm 110to use a layout suitable for a different architecture. 111Current valid values are 112.Cm i386 , amd64 , ia64 , pc98 , 113and 114.Cm alpha . 115If this option is omitted, 116.Nm 117will use a layout suitable for the current machine. 118.Ss Reading the Disk Label 119To examine the label on a disk drive, use 120.Nm 121without options: 122.Pp 123.Nm 124.Op Fl A 125.Op Fl m Ar machine 126.Ar disk 127.Pp 128.Ar disk 129represents the disk in question, and may be in the form 130.Pa da0 131or 132.Pa /dev/da0 . 133It will display the partition layout. 134.Ss Writing a Standard Label 135To write a standard label, use the form 136.Pp 137.Nm 138.Fl w 139.Op Fl \&An 140.Op Fl m Ar machine 141.Ar disk 142.Op Ar type 143.Pp 144If the drive type is specified, the entry of that name in the 145.Xr disktab 5 146file is used; otherwise a default layout is used. 147.Ss Editing an Existing Disk Label 148To edit an existing disk label, use the form 149.Pp 150.Nm 151.Fl e 152.Op Fl \&An 153.Op Fl m Ar machine 154.Ar disk 155.Pp 156This command opens the disk label in the default editor, and when the editor 157exits, the label is validated and if OK written to disk. 158.Ss Restoring a Disk Label From a File 159To restore a disk label from a file, use the form 160.Pp 161.Nm 162.Fl R 163.Op Fl \&An 164.Op Fl m Ar machine 165.Ar disk protofile 166.Pp 167.Nm 168is capable of restoring a disk label that was previously saved in a file in 169.Tn ASCII 170format. 171The prototype file used to create the label should be in the same format as that 172produced when reading or editing a label. 173Comments are delimited by 174.Ql # 175and newline. 176.Ss Installing Bootstraps 177If the 178.Fl B 179argument is specified, bootstrap code will be read from the file 180.Pa /boot/boot 181and written to the disk. 182The 183.Fl b Ar boot 184argument allows a different file to be used. 185.Sh FILES 186.Bl -tag -width ".Pa /etc/disktab" -compact 187.It Pa /boot/boot 188Default boot image. 189.It Pa /etc/disktab 190Disk description file. 191.El 192.Sh SAVED FILE FORMAT 193The 194.Nm 195utility 196uses an 197.Tn ASCII 198version of the label when examining, editing, or restoring a disk 199label. 200The format is: 201.Bd -literal -offset 4n 202 2038 partitions: 204# size offset fstype [fsize bsize bps/cpg] 205 a: 81920 16 4.2BSD 2048 16384 5128 206 b: 1091994 81936 swap 207 c: 1173930 0 unused 0 0 # "raw" part, don't edit 208.Ed 209.Pp 210If the 211.Fl A 212option is specified, the format is: 213.Bd -literal -offset 4n 214# /dev/da1c: 215type: SCSI 216disk: da0s1 217label: 218flags: 219bytes/sector: 512 220sectors/track: 51 221tracks/cylinder: 19 222sectors/cylinder: 969 223cylinders: 1211 224sectors/unit: 1173930 225rpm: 3600 226interleave: 1 227trackskew: 0 228cylinderskew: 0 229headswitch: 0 # milliseconds 230track-to-track seek: 0 # milliseconds 231drivedata: 0 232 2338 partitions: 234# size offset fstype [fsize bsize bps/cpg] 235 a: 81920 16 4.2BSD 1024 8192 16 236 b: 160000 81936 swap 237 c: 1173930 0 unused 0 0 # "raw" part, don't edit 238.Ed 239.Pp 240Lines starting with a 241.Ql # 242mark are comments. 243.Pp 244The partition table can have up to 8 entries. 245It contains the following information: 246.Bl -tag -width indent 247.It Ar # 248The partition identifier is a single letter in the range 249.Ql a 250to 251.Ql h . 252By convention, partition 253.Ql c 254is reserved to describe the entire disk. 255.It Ar size 256The size of the partition in sectors, 257.Cm K 258(kilobytes - 1024), 259.Cm M 260(megabytes - 1024*1024), 261.Cm G 262(gigabytes - 1024*1024*1024), 263.Cm % 264(percentage of free space 265.Em after 266removing any fixed-size partitions other than partition 267.Ql c ) , 268or 269.Cm * 270(all remaining free space 271.Em after 272fixed-size and percentage partitions). 273For partition 274.Ql c , 275a size of 276.Cm * 277indicates the entire disk. 278Lowercase versions of 279.Cm K , M , 280and 281.Cm G 282are allowed. 283Size and type should be specified without any spaces between them. 284.Pp 285Example: 2097152, 1G, 1024M and 1048576K are all the same size 286(assuming 512-byte sectors). 287.It Ar offset 288The offset of the start of the partition from the beginning of the 289drive in sectors, or 290.Cm * 291to have 292.Nm 293calculate the correct offset to use (the end of the previous partition plus 294one, ignoring partition 295.Ql c . 296For partition 297.Ql c , 298.Cm * 299will be interpreted as an offset of 0. 300The first partition should start at offset 16, because the first 16 sectors are 301reserved for metadata. 302.It Ar fstype 303Describes the purpose of the partition. 304The example shows all currently used partition types. 305For 306.Tn UFS 307file systems and 308.Xr ccd 4 309partitions, use type 310.Cm 4.2BSD . 311For Vinum drives, use type 312.Cm vinum . 313Other common types are 314.Cm swap 315and 316.Cm unused . 317By convention, partition 318.Ql c 319represents the entire slice and should be of type 320.Cm unused , 321though 322.Nm 323does not enforce this convention. 324The 325.Nm 326utility 327also knows about a number of other partition types, 328none of which are in current use. 329(See the definitions starting with 330.Dv FS_UNUSED 331in 332.In sys/disklabel.h 333for more details.) 334.It Ar fsize 335For 336.Cm 4.2BSD 337file systems only, the fragment size; see 338.Xr newfs 8 . 339.It Ar bsize 340For 341.Cm 4.2BSD 342file systems only, the block size; see 343.Xr newfs 8 . 344.It Ar bps/cpg 345For 346.Cm 4.2BSD 347file systems, the number of cylinders in a cylinder group; see 348.Xr newfs 8 . 349.El 350.Sh EXAMPLES 351.Dl "bsdlabel da0s1" 352.Pp 353Display the label for the first slice of the 354.Pa da0 355disk, as obtained via 356.Pa /dev/da0s1 . 357.Pp 358.Dl "bsdlabel da0s1 > savedlabel" 359.Pp 360Save the in-core label for 361.Pa da0s1 362into the file 363.Pa savedlabel . 364This file can be used with the 365.Fl R 366option to restore the label at a later date. 367.Pp 368.Dl "bsdlabel -w /dev/da0s1" 369.Pp 370Create a label for 371.Pa da0s1 . 372.Pp 373.Dl "bsdlabel -e da0s1" 374.Pp 375Read the label for 376.Pa da0s1 , 377edit it, and install the result. 378.Pp 379.Dl "bsdlabel -e -n da0s1" 380.Pp 381Read the on-disk label for 382.Pa da0s1 , 383edit it, and display what the new label would be (in sectors). 384It does 385.Em not 386install the new label either in-core or on-disk. 387.Pp 388.Dl "bsdlabel -w da0s1" 389.Pp 390Write a default label on 391.Pa da0s1 . 392Use another 393.Nm Fl e 394command to edit the 395partitioning and file system information. 396.Pp 397.Dl "bsdlabel -R da0s1 savedlabel" 398.Pp 399Restore the on-disk and in-core label for 400.Pa da0s1 401from information in 402.Pa savedlabel . 403.Pp 404.Dl "bsdlabel -R -n da0s1 label_layout" 405.Pp 406Display what the label would be for 407.Pa da0s1 408using the partition layout in 409.Pa label_layout . 410This is useful for determining how much space would be allotted for various 411partitions with a labeling scheme using 412.Cm % Ns -based 413or 414.Cm * 415partition sizes. 416.Pp 417.Dl "bsdlabel -B da0s1" 418.Pp 419Install a new bootstrap on 420.Pa da0s1 . 421The boot code comes from 422.Pa /boot/boot . 423.Pp 424.Dl "bsdlabel -w -B -b newboot /dev/da0s1" 425.Pp 426Install a new label and bootstrap. 427The bootstrap code comes from the file 428.Pa newboot 429in the current working directory. 430.Bd -literal -offset indent 431dd if=/dev/zero of=/dev/da0 bs=512 count=32 432fdisk -BI da0 433dd if=/dev/zero of=/dev/da0s1 bs=512 count=32 434bsdlabel -w -B da0s1 435bsdlabel -e da0s1 436.Ed 437.Pp 438Completely wipe any prior information on the disk, creating a new bootable 439disk with a 440.Tn DOS 441partition table containing one slice, covering the whole disk. 442Initialize the label on this slice, 443then edit it. 444The 445.Xr dd 1 446commands are optional, but may be necessary for some 447.Tn BIOS Ns es 448to properly 449recognize the disk. 450.Pp 451This is an example disk label that uses some of the new partition size types 452such as 453.Cm % , M , G , 454and 455.Cm * , 456which could be used as a source file for 457.Dq Li "bsdlabel -R ad0s1c new_label_file" : 458.Bd -literal -offset 4n 459# /dev/ad0s1c: 460 4618 partitions: 462# size offset fstype [fsize bsize bps/cpg] 463 a: 400M 16 4.2BSD 4096 16384 75 # (Cyl. 0 - 812*) 464 b: 1G * swap 465 c: * * unused 466 e: 204800 * 4.2BSD 467 f: 5g * 4.2BSD 468 g: * * 4.2BSD 469.Ed 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.Sh COMPATIBILITY 474Due to the use of an 475.Vt u_int32_t 476to store the number of sectors, 477.Bx 478labels are restricted to a maximum of 2^32-1 sectors. 479This usually means 2TB of disk space. 480Larger disks should be partitioned using another method such as 481.Xr gpt 8 . 482.Pp 483The various 484.Bx Ns s 485all use slightly different versions of 486.Bx 487labels and 488are not generally compatible. 489.Sh SEE ALSO 490.Xr ccd 4 , 491.Xr geom 4 , 492.Xr md 4 , 493.\" Xr bsdlabel 5 , 494.Xr disktab 5 , 495.Xr boot0cfg 8 , 496.Xr fdisk 8 , 497.Xr gpt 8 , 498.Xr newfs 8 499