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| 35 | .\" @(#)disklabel.8 8.2 (Berkeley) 4/19/94 |
| 36 | .\" $FreeBSD: src/sbin/disklabel/disklabel.8,v 1.15.2.22 2003/04/17 17:56:34 trhodes Exp $ |
| 37 | .\" |
| 38 | .Dd August 3, 2012 |
| 39 | .Dt DISKLABEL32 8 |
| 40 | .Os |
| 41 | .Sh NAME |
| 42 | .Nm disklabel32 |
| 43 | .Nd read and write 32 bit disk pack label |
| 44 | .Sh SYNOPSIS |
| 45 | .Nm |
| 46 | .Op Fl r |
| 47 | .Ar disk |
| 48 | .Nm |
| 49 | .Fl w |
| 50 | .Op Fl r |
| 51 | .Op Fl n |
| 52 | .Ar disk Ar disktype Ns / Ns Cm auto |
| 53 | .Oo Ar packid Oc |
| 54 | .Nm |
| 55 | .Fl e |
| 56 | .Op Fl r |
| 57 | .Op Fl n |
| 58 | .Ar disk |
| 59 | .Nm |
| 60 | .Fl R |
| 61 | .Op Fl r |
| 62 | .Op Fl n |
| 63 | .Ar disk Ar protofile |
| 64 | .Nm |
| 65 | .Op Fl NW |
| 66 | .Ar disk |
| 67 | .Pp |
| 68 | .Nm |
| 69 | .Fl B |
| 70 | .Oo |
| 71 | .Fl b Ar boot1 |
| 72 | .Fl s Ar boot2 |
| 73 | .Oc |
| 74 | .Ar disk |
| 75 | .Oo Ar disktype Ns / Ns Cm auto Oc |
| 76 | .Nm |
| 77 | .Fl w |
| 78 | .Fl B |
| 79 | .Op Fl n |
| 80 | .Oo |
| 81 | .Fl b Ar boot1 |
| 82 | .Fl s Ar boot2 |
| 83 | .Oc |
| 84 | .Ar disk Ar disktype Ns / Ns Cm auto |
| 85 | .Oo Ar packid Oc |
| 86 | .Nm |
| 87 | .Fl R |
| 88 | .Fl B |
| 89 | .Op Fl n |
| 90 | .Oo |
| 91 | .Fl b Ar boot1 |
| 92 | .Fl s Ar boot2 |
| 93 | .Oc |
| 94 | .Ar disk Ar protofile |
| 95 | .Oo Ar disktype Ns / Ns Cm auto Oc |
| 96 | .Nm |
| 97 | .Fl f Ar slice_start_lba |
| 98 | .Oo Ar options Oc |
| 99 | .Sh DESCRIPTION |
| 100 | The |
| 101 | .Nm |
| 102 | utility |
| 103 | installs, examines or modifies a 32 bit label on a disk drive or pack. |
| 104 | When writing |
| 105 | the label, it can be used to change the drive identification, the disk |
| 106 | partitions on the drive, or to replace a damaged label. |
| 107 | There are several forms |
| 108 | of the command that read (display), install or edit the label on a disk. |
| 109 | In |
| 110 | addition, |
| 111 | .Nm |
| 112 | can install bootstrap code. |
| 113 | .Ss Raw or in-core label |
| 114 | The disk label resides close to or at the beginning of each disk slice. |
| 115 | For faster access, the kernel maintains a copy in core at all times. |
| 116 | By |
| 117 | default, most forms of the |
| 118 | .Nm |
| 119 | command access the in-core copy of the label. |
| 120 | To access the raw (on-disk) |
| 121 | copy, use the |
| 122 | .Fl r |
| 123 | option. |
| 124 | This option allows a label to be installed on a disk without kernel |
| 125 | support for a label, such as when labels are first installed on a system; it |
| 126 | must be used when first installing a label on a disk. |
| 127 | The specific effect of |
| 128 | .Fl r |
| 129 | is described under each command. |
| 130 | .Ss Disk device name |
| 131 | All |
| 132 | .Nm |
| 133 | forms require a disk device name, which should always be the raw |
| 134 | device name representing the disk or slice. |
| 135 | .Dx |
| 136 | uses the following scheme for slice numbering: |
| 137 | If the disk doesn't use GPT (typically laid out by |
| 138 | .Xr gpt 8 ) , |
| 139 | but e.g.\& MBR (typically laid out by |
| 140 | .Xr fdisk 8 ) , |
| 141 | then slice 0, e.g.\& |
| 142 | .Pa da0s0 , |
| 143 | represents the entire disk regardless of any DOS partitioning. |
| 144 | Slice 0 is called the compatibility slice, |
| 145 | and slice 1 and onward, e.g.\& |
| 146 | .Pa da0s1 , |
| 147 | represents a |
| 148 | .Bx |
| 149 | slice. |
| 150 | If the disk does use GPT, then all slices are |
| 151 | .Bx |
| 152 | slices, slice 0 isn't special, it is just the first slice on the disk. |
| 153 | You do not have to include the |
| 154 | .Pa /dev/ |
| 155 | path prefix when specifying the device. |
| 156 | The |
| 157 | .Nm |
| 158 | utility will automatically prepend it. |
| 159 | .Ss Reading the disk label |
| 160 | To examine the label on a disk drive, use |
| 161 | .Nm |
| 162 | without options: |
| 163 | .Pp |
| 164 | .Nm |
| 165 | .Op Fl r |
| 166 | .Ar disk |
| 167 | .Pp |
| 168 | .Ar disk |
| 169 | represents the raw disk in question, and may be in the form |
| 170 | .Pa da0s1 |
| 171 | or |
| 172 | .Pa /dev/da0s1 . |
| 173 | It will display all of the parameters associated with the drive and its |
| 174 | partition layout. |
| 175 | Unless the |
| 176 | .Fl r |
| 177 | flag is given, |
| 178 | the kernel's in-core copy of the label is displayed; |
| 179 | if the disk has no label, or the partition types on the disk are incorrect, |
| 180 | the kernel may have constructed or modified the label. |
| 181 | If the |
| 182 | .Fl r |
| 183 | flag is given, |
| 184 | .Nm |
| 185 | reads the label from the raw disk and displays it. |
| 186 | Both versions are usually |
| 187 | identical except in the case where a label has not yet been initialized or |
| 188 | is corrupt. |
| 189 | .Ss Writing a standard label |
| 190 | To write a standard label, use the form |
| 191 | .Pp |
| 192 | .Nm |
| 193 | .Fl w |
| 194 | .Op Fl r |
| 195 | .Op Fl n |
| 196 | .Ar disk Ar disktype Ns / Ns Cm auto |
| 197 | .Oo Ar packid Oc |
| 198 | .Pp |
| 199 | The required arguments to |
| 200 | .Nm |
| 201 | are the drive to be labeled and the drive type as described in the |
| 202 | .Xr disktab 5 |
| 203 | file. |
| 204 | The drive parameters and partitions are taken from that file. |
| 205 | If |
| 206 | different disks of the same physical type are to have different partitions, it |
| 207 | will be necessary to have separate disktab entries describing each, or to edit |
| 208 | the label after installation as described below. |
| 209 | The optional argument is a |
| 210 | pack identification string, up to 16 characters long. |
| 211 | The pack id must be |
| 212 | quoted if it contains blanks. |
| 213 | .Pp |
| 214 | If the |
| 215 | .Fl n |
| 216 | flag is given, no data will be written to the device, and instead the |
| 217 | disklabel that would have been written will be printed to stdout. |
| 218 | .Pp |
| 219 | If the |
| 220 | .Fl r |
| 221 | flag is given, the disk sectors containing the label and bootstrap |
| 222 | will be written directly. |
| 223 | A side-effect of this is that any existing bootstrap code will be overwritten |
| 224 | and the disk rendered unbootable. |
| 225 | See the boot options below for a method of |
| 226 | writing the label and the bootstrap at the same time. |
| 227 | If |
| 228 | .Fl r |
| 229 | is not specified, |
| 230 | the existing label will be updated via the in-core copy and any bootstrap |
| 231 | code will be unaffected. |
| 232 | If the disk does not already have a label, the |
| 233 | .Fl r |
| 234 | flag must be used. |
| 235 | In either case, the kernel's in-core label is replaced. |
| 236 | .Pp |
| 237 | For a virgin disk that is not known to |
| 238 | .Xr disktab 5 , |
| 239 | .Ar disktype |
| 240 | can be specified as |
| 241 | .Cm auto . |
| 242 | In this case, the driver is requested to produce a virgin label for the |
| 243 | disk. |
| 244 | This might or might not be successful, depending on whether the |
| 245 | driver for the disk is able to get the required data without reading |
| 246 | anything from the disk at all. |
| 247 | It will likely succeed for all SCSI |
| 248 | disks, most IDE disks, and vnode devices. |
| 249 | Writing a label to the |
| 250 | disk is the only supported operation, and the |
| 251 | .Ar disk |
| 252 | itself must be provided as the canonical name, i.e.\& not as a full |
| 253 | path name. |
| 254 | .Pp |
| 255 | For most harddisks, a label based on percentages for most partitions (and |
| 256 | one partition with a size of |
| 257 | .Ql * ) |
| 258 | will produce a reasonable configuration. |
| 259 | .Pp |
| 260 | PC-based systems have special requirements in order for the BIOS to properly |
| 261 | recognize a |
| 262 | .Dx |
| 263 | disklabel. |
| 264 | Older systems may require what is known as a |
| 265 | .Dq dangerously dedicated |
| 266 | disklabel, which creates a fake DOS partition to work around problems older |
| 267 | BIOSes have with modern disk geometries. |
| 268 | On newer systems you generally want |
| 269 | to create a normal DOS partition using |
| 270 | .Ar fdisk |
| 271 | and then create a |
| 272 | .Dx |
| 273 | disklabel within that slice. |
| 274 | This is described |
| 275 | later on in this page. |
| 276 | .Pp |
| 277 | Installing a new disklabel does not in of itself allow your system to boot |
| 278 | a kernel using that label. |
| 279 | You must also install boot blocks, which is |
| 280 | described later on in this manual page. |
| 281 | .Ss Editing an existing disk label |
| 282 | To edit an existing disk label, use the form |
| 283 | .Pp |
| 284 | .Nm |
| 285 | .Fl e |
| 286 | .Op Fl r |
| 287 | .Op Fl n |
| 288 | .Ar disk |
| 289 | .Pp |
| 290 | This command reads the label from the in-core kernel copy, or directly from the |
| 291 | disk if the |
| 292 | .Fl r |
| 293 | flag is also specified. |
| 294 | The label is written to a file in ASCII and then |
| 295 | supplied to an editor for changes. |
| 296 | If no editor is specified in an |
| 297 | .Ev EDITOR |
| 298 | environment variable, |
| 299 | .Xr vi 1 |
| 300 | is used. |
| 301 | When the editor terminates, the label file is used to rewrite the disk label. |
| 302 | Existing bootstrap code is unchanged regardless of whether |
| 303 | .Fl r |
| 304 | was specified. |
| 305 | If |
| 306 | .Fl n |
| 307 | is specified, no data will be written to the device, and instead the |
| 308 | disklabel that would have been written will be printed to stdout. |
| 309 | This is |
| 310 | useful to see how a partitioning scheme will work out for a specific disk. |
| 311 | .Ss Restoring a disk label from a file |
| 312 | To restore a disk label from a file, use the form |
| 313 | .Pp |
| 314 | .Nm |
| 315 | .Fl R |
| 316 | .Op Fl r |
| 317 | .Op Fl n |
| 318 | .Ar disk Ar protofile |
| 319 | .Pp |
| 320 | .Nm |
| 321 | is capable of restoring a disk label that was previously saved in a file |
| 322 | in ASCII format. |
| 323 | The prototype file used to create the label should be in the same format |
| 324 | as that produced when reading or editing a label. |
| 325 | Comments are delimited by |
| 326 | .Ql # |
| 327 | and newline. |
| 328 | As when writing a new label, any existing bootstrap code will be |
| 329 | clobbered if |
| 330 | .Fl r |
| 331 | is specified and will be unaffected otherwise. |
| 332 | See the boot options below for a |
| 333 | method of restoring the label and writing the bootstrap at the same time. |
| 334 | If |
| 335 | .Fl n |
| 336 | is used, no data will be written to the device, and instead the |
| 337 | disklabel that would have been written will be printed to stdout. |
| 338 | This is |
| 339 | useful to see how a partitioning scheme will work out for a specific disk. |
| 340 | .Ss Enabling and disabling writing to the disk label area |
| 341 | By default, it is not possible to write to the disk label area at the beginning |
| 342 | of a disk. |
| 343 | The disk driver arranges for |
| 344 | .Xr write 2 |
| 345 | and similar system calls |
| 346 | to return |
| 347 | .Er EROFS |
| 348 | on any attempt to do so. |
| 349 | If you need |
| 350 | to write to this area (for example, to obliterate the label), use the form |
| 351 | .Pp |
| 352 | .Nm |
| 353 | .Fl W |
| 354 | .Ar disk |
| 355 | .Pp |
| 356 | To disallow writing to the label area after previously allowing it, |
| 357 | use the command |
| 358 | .Pp |
| 359 | .Nm |
| 360 | .Fl N |
| 361 | .Ar disk |
| 362 | .Ss Installing bootstraps |
| 363 | The final three forms of |
| 364 | .Nm |
| 365 | are used to install bootstrap code, which allows boot from a |
| 366 | .Xr UFS 5 |
| 367 | file system. |
| 368 | If you are creating a |
| 369 | .Dq dangerously-dedicated |
| 370 | slice for compatibility with older PC systems, |
| 371 | you generally want to specify the compatibility slice, such as |
| 372 | .Pa da0s0 . |
| 373 | If you are creating a label within an existing DOS slice, |
| 374 | you should specify |
| 375 | the slice name such as |
| 376 | .Pa da0s1 . |
| 377 | Making a slice bootable can be tricky. |
| 378 | If you are using a normal DOS |
| 379 | slice you typically install (or leave) a standard MBR on the base disk and |
| 380 | then install the |
| 381 | .Dx |
| 382 | bootblocks in the slice. |
| 383 | .Pp |
| 384 | .Nm |
| 385 | .Fl B |
| 386 | .Oo |
| 387 | .Fl b Ar boot1 |
| 388 | .Fl s Ar boot2 |
| 389 | .Oc |
| 390 | .Ar disk |
| 391 | .Oo Ar disktype Ns / Ns Cm auto Oc |
| 392 | .Pp |
| 393 | This form installs the bootstrap only. |
| 394 | It does not change the disk label. |
| 395 | You should never use this command on the compatibility slice unless you |
| 396 | intend to create a |
| 397 | .Dq dangerously-dedicated |
| 398 | disk, such as |
| 399 | .Ar da0s0 . |
| 400 | This command is typically run on a |
| 401 | .Bx |
| 402 | slice such as |
| 403 | .Ar da0s1 . |
| 404 | .Pp |
| 405 | .Nm |
| 406 | .Fl w |
| 407 | .Fl B |
| 408 | .Op Fl n |
| 409 | .Oo |
| 410 | .Fl b Ar boot1 |
| 411 | .Fl s Ar boot2 |
| 412 | .Oc |
| 413 | .Ar disk Ar disktype Ns / Ns Cm auto |
| 414 | .Oo Ar packid Oc |
| 415 | .Pp |
| 416 | This form corresponds to the |
| 417 | .Dq write label |
| 418 | command described above. |
| 419 | In addition to writing a new volume label, it also installs the bootstrap. |
| 420 | If run on the compatibility slice this command will create a |
| 421 | .Dq dangerously-dedicated |
| 422 | label. |
| 423 | This command is normally run on a |
| 424 | .Bx |
| 425 | slice rather than the compatibility slice. |
| 426 | If |
| 427 | .Fl n |
| 428 | is used, no data will be written to the device, and instead the |
| 429 | disklabel that would have been written will be printed to stdout. |
| 430 | .Pp |
| 431 | .Nm |
| 432 | .Fl R |
| 433 | .Fl B |
| 434 | .Op Fl n |
| 435 | .Oo |
| 436 | .Fl b Ar boot1 |
| 437 | .Fl s Ar boot2 |
| 438 | .Oc |
| 439 | .Ar disk Ar protofile |
| 440 | .Oo Ar disktype Ns / Ns Cm auto Oc |
| 441 | .Pp |
| 442 | This form corresponds to the |
| 443 | .Dq restore label |
| 444 | command described above. |
| 445 | In addition to restoring the volume label, it also installs the bootstrap. |
| 446 | If run on the compatibility slice this command will create a |
| 447 | .Dq dangerously-dedicated |
| 448 | label. |
| 449 | This command is normally run on a |
| 450 | .Bx |
| 451 | slice rather than the compatibility |
| 452 | slice. |
| 453 | .Pp |
| 454 | The bootstrap commands always access the disk directly, |
| 455 | so it is not necessary to specify the |
| 456 | .Fl r |
| 457 | flag. |
| 458 | If |
| 459 | .Fl n |
| 460 | is used, no data will be written to the device, and instead the |
| 461 | disklabel that would have been written will be printed to stdout. |
| 462 | .Pp |
| 463 | The bootstrap code is comprised of two boot programs. |
| 464 | Specify the name of the |
| 465 | boot programs to be installed in one of these ways: |
| 466 | .Bl -enum |
| 467 | .It |
| 468 | Specify the names explicitly with the |
| 469 | .Fl b |
| 470 | and |
| 471 | .Fl s |
| 472 | flags. |
| 473 | .Fl b |
| 474 | indicates the primary boot program and |
| 475 | .Fl s |
| 476 | the secondary boot program. |
| 477 | The boot programs are normally located in |
| 478 | .Pa /boot . |
| 479 | .It |
| 480 | If the |
| 481 | .Fl b |
| 482 | and |
| 483 | .Fl s |
| 484 | flags are not specified, but |
| 485 | .Ar disktype |
| 486 | was specified, the names of the programs are taken from the |
| 487 | .Dq b0 |
| 488 | and |
| 489 | .Dq b1 |
| 490 | parameters of the |
| 491 | .Xr disktab 5 |
| 492 | entry for the disk if the disktab entry exists and includes those parameters. |
| 493 | .It |
| 494 | Otherwise, the default boot image names are used: |
| 495 | .Pa /boot/boot1 |
| 496 | and |
| 497 | .Pa /boot/boot2 |
| 498 | for the standard stage1 and stage2 boot images. |
| 499 | .El |
| 500 | .Ss Initializing/Formatting a bootable disk from scratch |
| 501 | To initialize a disk from scratch the following sequence is recommended. |
| 502 | Please note that this will wipe everything that was previously on the disk, |
| 503 | including any |
| 504 | .No non- Ns Dx |
| 505 | slices. |
| 506 | .Bl -enum |
| 507 | .It |
| 508 | Use |
| 509 | .Xr gpt 8 |
| 510 | or |
| 511 | .Xr fdisk 8 |
| 512 | to initialize the hard disk, and create a GPT or MBR slice table, |
| 513 | referred to as the |
| 514 | .Dq "partition table" |
| 515 | in |
| 516 | .Tn DOS . |
| 517 | .It |
| 518 | Use |
| 519 | .Nm |
| 520 | or |
| 521 | .Xr disklabel64 8 |
| 522 | to define partitions on |
| 523 | .Dx |
| 524 | slices created in the previous step. |
| 525 | .It |
| 526 | Finally use |
| 527 | .Xr newfs_hammer 8 |
| 528 | or |
| 529 | .Xr newfs 8 |
| 530 | to create file systems on new partitions. |
| 531 | .El |
| 532 | .Pp |
| 533 | A typical partitioning scheme would be to have an |
| 534 | .Ql a |
| 535 | partition |
| 536 | of approximately 512MB to hold the root file system, a |
| 537 | .Ql b |
| 538 | partition for |
| 539 | swap (usually 4GB), a |
| 540 | .Ql d |
| 541 | partition for |
| 542 | .Pa /var |
| 543 | (usually 2GB), an |
| 544 | .Ql e |
| 545 | partition for |
| 546 | .Pa /var/tmp |
| 547 | (usually 2GB), an |
| 548 | .Ql f |
| 549 | partition for |
| 550 | .Pa /usr |
| 551 | (usually around 4GB), |
| 552 | and finally a |
| 553 | .Ql g |
| 554 | partition for |
| 555 | .Pa /home |
| 556 | (usually all remaining space). |
| 557 | If you are tight on space all sizes can be halved. |
| 558 | Your mileage may vary. |
| 559 | .Pp |
| 560 | .Dl "fdisk -BI da0" |
| 561 | .Dl "disklabel32 -w -B da0s1 auto" |
| 562 | .Dl "disklabel32 -e da0s1" |
| 563 | .Ss Manual offset |
| 564 | .Dx |
| 565 | no longer snoop-adjusts the on-disk label when reading or writing |
| 566 | raw labels. |
| 567 | .Nm |
| 568 | is now responsible for adjusting the label when operating in raw mode. |
| 569 | Traditional (32 bit, |
| 570 | .Bx ) |
| 571 | disklabels store offsets as absolute block numbers |
| 572 | rather than slice-relative block numbers. |
| 573 | If |
| 574 | .Nm |
| 575 | is unable to issue the |
| 576 | .Dv DIOCGPART |
| 577 | ioctl to get slice information it will |
| 578 | refuse to read or write the label in raw mode. |
| 579 | The |
| 580 | .Fl f |
| 581 | option may be used to force the operation by supplying a manual offset. |
| 582 | .Sh FILES |
| 583 | .Bl -tag -width ".Pa /etc/disktab" -compact |
| 584 | .It Pa /boot/boot1 |
| 585 | Default stage1 boot image. |
| 586 | .It Pa /boot/boot2 |
| 587 | Default stage2 boot image. |
| 588 | .It Pa /etc/disktab |
| 589 | Disk description file. |
| 590 | .El |
| 591 | .Sh SAVED FILE FORMAT |
| 592 | The |
| 593 | .Nm |
| 594 | utility uses an |
| 595 | .Tn ASCII |
| 596 | version of the label when examining, editing, or restoring a disk label. |
| 597 | The format is: |
| 598 | .Bd -literal -offset 4n |
| 599 | # /dev/ad4s4: |
| 600 | type: unknown |
| 601 | disk: amnesiac |
| 602 | label: fictitious |
| 603 | flags: |
| 604 | bytes/sector: 512 |
| 605 | sectors/track: 63 |
| 606 | tracks/cylinder: 24 |
| 607 | sectors/cylinder: 1512 |
| 608 | cylinders: 161098 |
| 609 | sectors/unit: 243581184 |
| 610 | rpm: 3600 |
| 611 | interleave: 1 |
| 612 | trackskew: 0 |
| 613 | cylinderskew: 0 |
| 614 | headswitch: 0 # milliseconds |
| 615 | track-to-track seek: 0 # milliseconds |
| 616 | drivedata: 0 |
| 617 | |
| 618 | 16 partitions: |
| 619 | # size offset fstype |
| 620 | a: 1048560 16 4.2BSD # 511.992MB |
| 621 | b: 8388608 1048576 swap # 4096.000MB |
| 622 | c: 243581184 0 unused # 118936.125MB |
| 623 | d: 4194304 9437184 4.2BSD # 2048.000MB |
| 624 | e: 4194304 13631488 4.2BSD # 2048.000MB |
| 625 | f: 8388608 17825792 4.2BSD # 4096.000MB |
| 626 | h: 196395264 26214400 HAMMER # 95896.125MB |
| 627 | i: 10485760 222609664 ccd # 5120.000MB |
| 628 | j: 10485760 233095424 vinum # 5120.000MB |
| 629 | .Ed |
| 630 | .Pp |
| 631 | Lines starting with a |
| 632 | .Ql # |
| 633 | mark are comments. |
| 634 | Most of the other specifications are no longer used. |
| 635 | The ones which must still be set correctly are: |
| 636 | .Bl -inset |
| 637 | .It Ar label |
| 638 | is an optional label, set by the |
| 639 | .Ar packid |
| 640 | option when writing a label. |
| 641 | .It Ar flags |
| 642 | may be |
| 643 | .Cm removable , ecc |
| 644 | or |
| 645 | .Cm badsect . |
| 646 | .Cm removable |
| 647 | is set for removable media drives, but no current |
| 648 | .Dx |
| 649 | driver evaluates this |
| 650 | flag. |
| 651 | .Cm ecc |
| 652 | is no longer supported; |
| 653 | .Cm badsect |
| 654 | specifies that the drive can perform bad sector remapping. |
| 655 | .It Ar sectors/unit |
| 656 | describes the total size of the disk. |
| 657 | This value must be correct. |
| 658 | .It Ar "the partition table" |
| 659 | is the |
| 660 | .Ux |
| 661 | partition table, not the |
| 662 | .Tn DOS |
| 663 | partition table described in |
| 664 | .Xr fdisk 8 . |
| 665 | .El |
| 666 | .Pp |
| 667 | The partition table can have up to 16 entries. |
| 668 | It contains the following information: |
| 669 | .Bl -tag -width indent |
| 670 | .It Ar # |
| 671 | The partition identifier is a single letter in the range |
| 672 | .Ql a |
| 673 | to |
| 674 | .Ql p . |
| 675 | By convention, partition |
| 676 | .Ql c |
| 677 | is reserved to describe the entire disk. |
| 678 | .It Ar size |
| 679 | The size of the partition in sectors, |
| 680 | .Cm K |
| 681 | (kilobytes - 1024), |
| 682 | .Cm M |
| 683 | (megabytes - 1024*1024), |
| 684 | .Cm G |
| 685 | (gigabytes - 1024*1024*1024), |
| 686 | .Cm T |
| 687 | (gigabytes - 1024*1024*1024*1024), |
| 688 | .Cm % |
| 689 | (percentage of free space |
| 690 | .Em after |
| 691 | removing any fixed-size partitions other than partition |
| 692 | .Ql c ) , |
| 693 | or |
| 694 | .Cm * |
| 695 | (all remaining free space |
| 696 | .Em after |
| 697 | fixed-size and percentage partitions). |
| 698 | For partition |
| 699 | .Ql c , |
| 700 | a size of |
| 701 | .Cm * |
| 702 | indicates the entire disk. |
| 703 | Lowercase versions of |
| 704 | .Cm K , M , G , |
| 705 | and |
| 706 | .Cm T |
| 707 | are allowed. |
| 708 | Size and type should be specified without any spaces between them. |
| 709 | .Pp |
| 710 | Example: 2097152, 1G, 1024M and 1048576K are all the same size |
| 711 | (assuming 512-byte sectors). |
| 712 | .It Ar offset |
| 713 | The offset of the start of the partition from the beginning of the |
| 714 | drive in sectors, or |
| 715 | .Cm * |
| 716 | to have |
| 717 | .Nm |
| 718 | calculate the correct offset to use (the end of the previous partition plus |
| 719 | one, ignoring partition |
| 720 | .Ql c . |
| 721 | For partition |
| 722 | .Ql c , |
| 723 | .Cm * |
| 724 | will be interpreted as an offset of 0. |
| 725 | .It Ar fstype |
| 726 | Describes the purpose of the partition. |
| 727 | The example shows all currently used partition types. |
| 728 | For |
| 729 | .Xr UFS 5 |
| 730 | file systems, use type |
| 731 | .Cm 4.2BSD . |
| 732 | For |
| 733 | .Xr HAMMER 5 |
| 734 | file systems, use type |
| 735 | .Cm HAMMER . |
| 736 | For |
| 737 | .Xr ccd 4 |
| 738 | partitions, use type |
| 739 | .Cm ccd . |
| 740 | For Vinum drives, use type |
| 741 | .Cm vinum . |
| 742 | Other common types are |
| 743 | .Cm swap |
| 744 | and |
| 745 | .Cm unused . |
| 746 | By convention, partition |
| 747 | .Ql c |
| 748 | represents the entire slice and should be of type |
| 749 | .Cm unused , |
| 750 | though |
| 751 | .Nm |
| 752 | does not enforce this convention. |
| 753 | The |
| 754 | .Nm |
| 755 | utility |
| 756 | also knows about a number of other partition types, |
| 757 | none of which are in current use. |
| 758 | (See |
| 759 | .Dv fstypenames |
| 760 | in |
| 761 | .In sys/dtype.h |
| 762 | for more details). |
| 763 | .El |
| 764 | .Pp |
| 765 | The remainder of the line is a comment and shows the size of |
| 766 | the partition in MB. |
| 767 | .Sh EXAMPLES |
| 768 | .Dl "disklabel32 da0s1" |
| 769 | .Pp |
| 770 | Display the in-core label for the first slice of the |
| 771 | .Pa da0 |
| 772 | disk, as obtained via |
| 773 | .Pa /dev/da0s1 . |
| 774 | (If the disk is |
| 775 | .Dq dangerously-dedicated , |
| 776 | the compatibility slice name should be specified, such as |
| 777 | .Pa da0s0 . ) |
| 778 | .Pp |
| 779 | .Dl "disklabel32 da0s1 > savedlabel" |
| 780 | .Pp |
| 781 | Save the in-core label for |
| 782 | .Pa da0s1 |
| 783 | into the file |
| 784 | .Pa savedlabel . |
| 785 | This file can be used with the |
| 786 | .Fl R |
| 787 | option to restore the label at a later date. |
| 788 | .Pp |
| 789 | .Dl "disklabel32 -w -r /dev/da0s1 da2212 foo" |
| 790 | .Pp |
| 791 | Create a label for |
| 792 | .Pa da0s1 |
| 793 | based on information for |
| 794 | .Dq da2212 |
| 795 | found in |
| 796 | .Pa /etc/disktab . |
| 797 | Any existing bootstrap code will be clobbered |
| 798 | and the disk rendered unbootable. |
| 799 | .Pp |
| 800 | .Dl "disklabel32 -e -r da0s1" |
| 801 | .Pp |
| 802 | Read the on-disk label for |
| 803 | .Pa da0s1 , |
| 804 | edit it, and reinstall in-core as well as on-disk. |
| 805 | Existing bootstrap code is unaffected. |
| 806 | .Pp |
| 807 | .Dl "disklabel32 -e -r -n da0s1" |
| 808 | .Pp |
| 809 | Read the on-disk label for |
| 810 | .Pa da0s1 , |
| 811 | edit it, and display what the new label would be (in sectors). |
| 812 | It does |
| 813 | .Em not |
| 814 | install the new label either in-core or on-disk. |
| 815 | .Pp |
| 816 | .Dl "disklabel32 -r -w da0s1 auto" |
| 817 | .Pp |
| 818 | Try to auto-detect the required information from |
| 819 | .Pa da0s1 , |
| 820 | and write a new label to the disk. |
| 821 | Use another |
| 822 | .Nm Fl e |
| 823 | command to edit the |
| 824 | partitioning and file system information. |
| 825 | .Pp |
| 826 | .Dl "disklabel32 -R da0s1 savedlabel" |
| 827 | .Pp |
| 828 | Restore the on-disk and in-core label for |
| 829 | .Pa da0s1 |
| 830 | from information in |
| 831 | .Pa savedlabel . |
| 832 | Existing bootstrap code is unaffected. |
| 833 | .Pp |
| 834 | .Dl "disklabel32 -R -n da0s1 label_layout" |
| 835 | .Pp |
| 836 | Display what the label would be for |
| 837 | .Pa da0s1 |
| 838 | using the partition layout in |
| 839 | .Pa label_layout . |
| 840 | This is useful for determining how much space would be allotted for various |
| 841 | partitions with a labelling scheme using |
| 842 | .Cm % Ns -based |
| 843 | or |
| 844 | .Cm * |
| 845 | partition sizes. |
| 846 | .Pp |
| 847 | .Dl "disklabel32 -B da0s1" |
| 848 | .Pp |
| 849 | Install a new bootstrap on |
| 850 | .Pa da0s1 . |
| 851 | The boot code comes from |
| 852 | .Pa /boot/boot1 |
| 853 | and possibly |
| 854 | .Pa /boot/boot2 . |
| 855 | On-disk and in-core labels are unchanged. |
| 856 | .Pp |
| 857 | .Dl "disklabel32 -w -B /dev/da0s1 -b newboot1 -s newboot2 da2212" |
| 858 | .Pp |
| 859 | Install a new label and bootstrap. |
| 860 | The label is derived from disktab information for |
| 861 | .Dq da2212 |
| 862 | and installed both in-core and on-disk. |
| 863 | The bootstrap code comes from the files |
| 864 | .Pa newboot1 |
| 865 | and |
| 866 | .Pa newboot2 . |
| 867 | .Pp |
| 868 | .Dl "dd if=/dev/zero of=/dev/da0 bs=512 count=32" |
| 869 | .Dl "fdisk -BI da0" |
| 870 | .Dl "dd if=/dev/zero of=/dev/da0s1 bs=512 count=32" |
| 871 | .Dl "disklabel32 -w -B da0s1 auto" |
| 872 | .Dl "disklabel32 -e da0s1" |
| 873 | .Pp |
| 874 | Completely wipe any prior information on the disk, creating a new bootable |
| 875 | disk with a DOS partition table containing one |
| 876 | .Dq whole-disk |
| 877 | slice. |
| 878 | Then |
| 879 | initialize the slice, then edit it to your needs. |
| 880 | The |
| 881 | .Pa dd |
| 882 | commands are optional, but may be necessary for some BIOSes to properly |
| 883 | recognize the disk. |
| 884 | .Pp |
| 885 | .Dl "disklabel32 -W da0s1" |
| 886 | .Dl "dd if=/dev/zero of=/dev/da0s1 bs=512 count=32" |
| 887 | .Dl "disklabel64 -r -w da0s1 auto" |
| 888 | .Dl "disklabel64 -N da0s1" |
| 889 | .Pp |
| 890 | Completely wipe any prior information on the slice, |
| 891 | changing label format to 64 bit. |
| 892 | The wiping is needed as |
| 893 | .Nm disklabel64 |
| 894 | and |
| 895 | .Nm , |
| 896 | as a safety measure, |
| 897 | won't do any operations if label with other format is already installed. |
| 898 | .Pp |
| 899 | This is an example disklabel that uses some of the new partition size types |
| 900 | such as |
| 901 | .Cm % , M , G , |
| 902 | and |
| 903 | .Cm * , |
| 904 | which could be used as a source file for |
| 905 | .Pp |
| 906 | .Dl "disklabel32 -R ad0s1 new_label_file" |
| 907 | .Bd -literal -offset 4n |
| 908 | # /dev/ad0s1: |
| 909 | type: ESDI |
| 910 | disk: ad0s1 |
| 911 | label: |
| 912 | flags: |
| 913 | bytes/sector: 512 |
| 914 | sectors/track: 63 |
| 915 | tracks/cylinder: 16 |
| 916 | sectors/cylinder: 1008 |
| 917 | cylinders: 40633 |
| 918 | sectors/unit: 40959009 |
| 919 | rpm: 3600 |
| 920 | interleave: 1 |
| 921 | trackskew: 0 |
| 922 | cylinderskew: 0 |
| 923 | headswitch: 0 # milliseconds |
| 924 | track-to-track seek: 0 # milliseconds |
| 925 | drivedata: 0 |
| 926 | |
| 927 | 16 partitions: |
| 928 | # size offset fstype |
| 929 | a: 400M 0 4.2BSD |
| 930 | b: 1G * swap |
| 931 | c: * * unused |
| 932 | e: 204800 * 4.2BSD |
| 933 | f: 5g * 4.2BSD |
| 934 | g: * * 4.2BSD |
| 935 | .Ed |
| 936 | .Sh DIAGNOSTICS |
| 937 | The kernel device drivers will not allow the size of a disk partition |
| 938 | to be decreased or the offset of a partition to be changed while it is open. |
| 939 | Some device drivers create a label containing only a single large partition |
| 940 | if a disk is unlabeled; thus, the label must be written to the |
| 941 | .Ql a |
| 942 | partition of the disk while it is open. |
| 943 | This sometimes requires the desired |
| 944 | label to be set in two steps, the first one creating at least one other |
| 945 | partition, and the second setting the label on the new partition while |
| 946 | shrinking the |
| 947 | .Ql a |
| 948 | partition. |
| 949 | .Pp |
| 950 | On some machines the bootstrap code may not fit entirely in the area |
| 951 | allocated for it by some file systems. |
| 952 | As a result, it may not be possible to have file systems on some partitions |
| 953 | of a |
| 954 | .Dq bootable |
| 955 | disk. |
| 956 | When installing bootstrap code, |
| 957 | .Nm |
| 958 | checks for these cases. |
| 959 | If the installed boot code would overlap a partition of type |
| 960 | .Dv FS_UNUSED |
| 961 | it is marked as type |
| 962 | .Dv FS_BOOT . |
| 963 | The |
| 964 | .Xr newfs 8 |
| 965 | utility will disallow creation of file systems on |
| 966 | .Dv FS_BOOT |
| 967 | partitions. |
| 968 | Conversely, if a partition has a type other than |
| 969 | .Dv FS_UNUSED |
| 970 | or |
| 971 | .Dv FS_BOOT , |
| 972 | .Nm |
| 973 | will not install bootstrap code that overlaps it. |
| 974 | .Sh COMPATIBILITY |
| 975 | Due to |
| 976 | .Xr disklabel32 5 |
| 977 | storing sector numbers in 32 bit format |
| 978 | .Nm |
| 979 | is restricted to 2TB, using the prevalent sector size of 512B. |
| 980 | .Xr disklabel64 5 |
| 981 | labels should be used to partition larger disks. |
| 982 | .Pp |
| 983 | The various |
| 984 | .Bx Ns s |
| 985 | use slightly different versions of |
| 986 | .Bx |
| 987 | disklabels |
| 988 | and are not generally compatible. |
| 989 | The |
| 990 | .Dx |
| 991 | kernel can often use labels from other |
| 992 | .Bx Ns s |
| 993 | for read-only operation. |
| 994 | .Sh SEE ALSO |
| 995 | .Xr dd 1 , |
| 996 | .Xr ccd 4 , |
| 997 | .Xr disklabel32 5 , |
| 998 | .Xr disktab 5 , |
| 999 | .Xr boot0cfg 8 , |
| 1000 | .Xr diskinfo 8 , |
| 1001 | .Xr disklabel64 8 , |
| 1002 | .Xr fdisk 8 , |
| 1003 | .Xr gpt 8 , |
| 1004 | .Xr newfs 8 , |
| 1005 | .Xr newfs_hammer 8 , |
| 1006 | .Xr vinum 8 |
| 1007 | .Sh BUGS |
| 1008 | For the i386 architecture, the primary bootstrap sector contains |
| 1009 | an embedded |
| 1010 | .Em fdisk |
| 1011 | table. |
| 1012 | The |
| 1013 | .Nm |
| 1014 | utility takes care to not clobber it when installing a bootstrap only |
| 1015 | .Pq Fl B , |
| 1016 | or when editing an existing label |
| 1017 | .Pq Fl e , |
| 1018 | but it unconditionally writes the primary bootstrap program onto |
| 1019 | the disk for |
| 1020 | .Fl w |
| 1021 | or |
| 1022 | .Fl R , |
| 1023 | thus replacing the |
| 1024 | .Em fdisk |
| 1025 | table by the dummy one in the bootstrap program. |
| 1026 | This is only of |
| 1027 | concern if the disk is fully dedicated, so that the |
| 1028 | .Bx |
| 1029 | disklabel |
| 1030 | starts at absolute block 0 on the disk. |
| 1031 | .Pp |
| 1032 | The |
| 1033 | .Nm |
| 1034 | utility |
| 1035 | does not perform all possible error checking. |
| 1036 | Warning |
| 1037 | .Em is |
| 1038 | given if partitions |
| 1039 | overlap; if an absolute offset does not match the expected offset; if the |
| 1040 | .Ql c |
| 1041 | partition does not start at 0 or does not cover the entire slice; if a |
| 1042 | partition runs past the end of the device; and a number of other errors; but |
| 1043 | no warning is given if space remains unused. |