1fdisk(1M)               System Administration Commands               fdisk(1M)
2
3
4

NAME

6       fdisk - create or modify fixed disk partition table
7

SYNOPSIS

9       fdisk [-o offset] [-s size] [-P fill_patt] [-S geom_file]
10            [-w | -r | -d | -n | -I | -B | -t | -T | -g | -G | -R | -E]
11            [--F fdisk_file] [ [-v] -W {fdisk_file | −}]
12            [-h] [-b masterboot]
13            [-A id : act : bhead : bsect : bcyl : ehead : esect :
14                ecyl : rsect : numsect]
15            [-D id : act : bhead: bsect : bcyl : ehead: esect :
16                ecyl : rsect : numsect] rdevice
17
18

DESCRIPTION

20       This command is used to do the following:
21
22           o      Create and modify an fdisk partition table on x86 systems
23
24           o      Create  and  modify  an  fdisk  partition table on removable
25                  media on SPARC or x86 systems
26
27           o      Install the master boot record that is put in the first sec‐
28                  tor of the fixed disk on x86 systems only
29
30
31       This  table is used by the first-stage bootstrap (or firmware) to iden‐
32       tify parts of the disk reserved for different operating systems, and to
33       identify  the  partition  containing  the  second-stage  bootstrap (the
34       active Solaris partition). The rdevice argument must be used to specify
35       the   raw   device   associated  with  the  fixed  disk,  for  example,
36       /dev/rdsk/c0t0d0p0.
37
38
39       The program can operate in three different modes. The first is interac‐
40       tive  mode. In interactive mode, the program displays the partition ta‐
41       ble as it exists on the disk, and then presents  a  menu  allowing  the
42       user to modify the table. The menu, questions, warnings, and error mes‐
43       sages are intended to be self-explanatory.
44
45
46       In interactive mode, if there is no partition table on  the  disk,  the
47       user  is given the options of creating a default partitioning or speci‐
48       fying the initial table values. The default partitioning allocates  the
49       entire  disk for the Solaris system and makes the Solaris system parti‐
50       tion active. In either case, when the initial table is  created,  fdisk
51       also  writes  out  the first-stage bootstrap (x86 only) code along with
52       the partition table. In this mode, (x86 only) when creating  an   entry
53       for a non-EFI partition on a disk that is larger than 2 TB (terabytes),
54       fdisk warns that the maximum size of the partition is 2 TB. Under these
55       conditions percentages displayed by fdisk are based on 2 TB.
56
57
58       The  second  mode  of  operation  is used for automated entry addition,
59       entry deletion, or replacement of the entire fdisk table. This mode can
60       add  or delete an entry described on the command line. In this mode the
61       entire fdisk table can be read in from a file  replacing  the  original
62       table.  fdisk  can also be used to create this file. There is a command
63       line option that will cause fdisk to replace any fdisk table  with  the
64       default of the whole disk for the Solaris system.
65
66
67       The third mode of operation is used for disk diagnostics. In this mode,
68       a section of the disk can be filled with a user-specified  pattern  and
69       mode sections of the disk can also be read or written.
70
71       Note -
72
73         The  third  mode of operation is not currently supported for extended
74         partitions
75
76
77       When fdisk creates a partition, the space is  allocated  in  the  fdisk
78       partition  table,  but  the  allocated  disk  space is not initialized.
79       newfs(1M) is required to create and write file system metadata  to  the
80       new  partition, and format(1M) is required to write the VTOC or EFI/GPT
81       metadata.
82
83   Menu Options
84       The menu options for interactive mode given by the fdisk program are:
85
86       Create a partition
87
88           This option allows the user to create a new partition. The  maximum
89           number of partitions is 4. The program will ask for the type of the
90           partition (SOLARIS, MS-DOS, UNIX, or other). It will then  ask  for
91           the size of the partition as a percentage of the disk. The user may
92           also enter the letter c at this point, in which  case  the  program
93           will ask for the starting cylinder number and size of the partition
94           in cylinders. If a c is not entered, the program will determine the
95           starting  cylinder  number  where the partition will fit. In either
96           case, if the partition would overlap an existing partition or  will
97           not  fit,  a  message  is  displayed and the program returns to the
98           original menu.
99
100
101       Change Active (Boot from) partition
102
103           This option allows the user to  specify  the  partition  where  the
104           first-stage  bootstrap  will  look  for the second-stage bootstrap,
105           otherwise known as the active partition.
106
107
108       Delete a partition
109
110           This option allows the user to delete a previously  created  parti‐
111           tion. Note that this will destroy all data in that partition.
112
113
114       Change between Solaris and Solaris2 Partition IDs
115
116           This  option  allows  the  user to switch between the current fdisk
117           operating system partition identifier and the  previous  one.  This
118           does  not affect any data in the disk partition and is provided for
119           compatibility with older software.
120
121
122       Edit/View extended partitions
123
124           This option provides the extended partition menu to the  user.  Use
125           the  extended  partition  menu  to  add  and delete logical drives,
126           change the sysid of the logical drives, and display  logical  drive
127           information.  To commit the changes made in the extended partition,
128           you must return to the main menu using the extended partition  sub‐
129           menu  option  r.  There  is  also  an option to display the list of
130           options that the extended partition submenu supports.  Given  below
131           is the list:
132
133           a    Add a logical drive.
134
135                Use  this  submenu  option  to  add a logical drive. There are
136                three pieces of information that are required:  The  beginning
137                cylinder,  the  size (in cylinders or in human readable form -
138                KB, MB, or GB), and the partition  ID.  While  specifying  the
139                partition  ID, there is an option (I) that you can use to list
140                the supported partitions.
141
142
143           d    Delete a logical drive.
144
145                Use this submenu option to delete a logical  drive.  The  only
146                input  required  is the number of the logical drive that is to
147                be deleted.
148
149
150           h    Display the help menu.
151
152                This submenu option displays the supported operations  in  the
153                extended partition submenu.
154
155
156           i    Change the id of the logical drive.
157
158                Use  this submenu option to change the system ID of the exist‐
159                ing logical drives. A list of supported  system  IDs  is  dis‐
160                played when you use the I option when in this submenu.
161
162
163           p    Display the logical drive layout.
164
165                Displays  the logical drive information to stdout. This output
166                reflects any changes made during the current run of the  fdisk
167                program.  The  changes  are  not  committed  to the disk until
168                return to the main menu (using the submenu r) and  choose  the
169                option to commit the changes to the disk.
170
171
172           r    Return to the main fdisk menu.
173
174                Exit  the  extended  partition  submenu and return to the main
175                menu.
176
177
178
179
180       Use the following options to include your modifications to  the  parti‐
181       tion  table at this time or to cancel the session without modifying the
182       table:
183
184       Exit      This option writes the new version of the table created  dur‐
185                 ing  this session with fdisk out to the fixed disk, and exits
186                 the program.
187
188
189       Cancel    This option exits without modifying the partition table.
190
191

OPTIONS

193       The following options apply to fdisk:
194
195       -A id:act:bhead:bsect:bcyl:ehead:esect:ecyl:rsect:numsect
196
197           Add a partition as described by the argument  (see  the  -F  option
198           below for the format). Use of this option will zero out the VTOC on
199           the Solaris partition if the fdisk table changes.
200
201
202       -b master_boot
203
204           Specify the file  master_boot  as  the  master  boot  program.  The
205           default master boot program is /usr/lib/fs/ufs/mboot.
206
207
208       -B
209
210           Default  to  one  Solaris partition that uses the whole disk. On an
211           x86 machine, if the disk is  larger  than  2  TB  (terabytes),  the
212           default size of the Solaris partition will be limited to 2 TB.
213
214
215       -d
216
217           Turn  on  verbose  debug  mode.  This will cause fdisk to print its
218           state on stderr as it is used. The output from this  option  should
219           not be used with -F.
220
221
222       -D id:act:bhead:bsect:bcyl:ehead:esect:ecyl:rsect:numsect
223
224           Delete  a partition as described by the argument (see the -F option
225           below for the format). Note that the  argument  must  be  an  exact
226           match  or  the  entry  will not be deleted! Use of this option will
227           zero out the VTOC on the  Solaris  partition  if  the  fdisk  table
228           changes.
229
230
231       -E
232
233           Create an EFI partition that uses the entire disk.
234
235
236       -F fdisk_file
237
238           Use  fdisk  file fdisk_file to initialize table. Use of this option
239           will zero out the VTOC on the Solaris partition if the fdisk  table
240           changes.
241
242           The  fdisk_file  contains  four specification lines for the primary
243           partitions followed by specification lines for the logical  drives.
244           You  must have four lines for the primary partitions if there is at
245           least one logical drive. In this case, if  the  number  of  primary
246           partitions  to be configured is less than four, the remaining lines
247           should be filled with zeros.
248
249           Each line is composed of entries that are  position-dependent,  are
250           separated by whitespace or colons, and have the following format:
251
252           id act bhead bsect bcyl ehead esect ecyl rsect numsect
253
254           ...where the entries have the following values:
255
256           id         This  is  the  type of partition and the correct numeric
257                      values may be found in fdisk.h.
258
259
260           act        This is the active partition flag; 0  means  not  active
261                      and 128 means active. For logical drives, this flag will
262                      always be set to 0 even if specified as 128 by the user.
263
264
265           bhead      This is the head where the partition starts. If this  is
266                      set  to  0, fdisk will correctly fill this in from other
267                      information.
268
269
270           bsect      This is the sector where the partition starts.  If  this
271                      is  set  to  0,  fdisk  will correctly fill this in from
272                      other information.
273
274
275           bcyl       This is the cylinder where the partition starts. If this
276                      is  set  to  0,  fdisk  will correctly fill this in from
277                      other information.
278
279
280           ehead      This is the head where the partition ends.  If  this  is
281                      set  to  0, fdisk will correctly fill this in from other
282                      information.
283
284
285           esect      This is the sector where the partition ends. If this  is
286                      set  to  0, fdisk will correctly fill this in from other
287                      information.
288
289
290           ecyl       This is the cylinder where the partition ends.  If  this
291                      is  set  to  0,  fdisk  will correctly fill this in from
292                      other information.
293
294
295           rsect      The relative sector from the beginning of the disk where
296                      the  partition starts. This must be specified and can be
297                      used by fdisk to  fill  in  other  fields.  For  logical
298                      drives,  you  must  make sure that there are at least 63
299                      free sectors before the rsect specified  for  a  logical
300                      drive.
301
302
303           numsect    The size in sectors of this disk partition. This must be
304                      specified and can be used by  fdisk  to  fill  in  other
305                      fields.
306
307
308
309       -g
310
311           Get  the  label geometry for disk and display on stdout (see the -S
312           option for the format).
313
314
315       -G
316
317           Get the physical geometry for disk and display on stdout  (see  the
318           -S option for the format).
319
320
321       -h
322
323           Issue  verbose message; message will list all options and supply an
324           explanation for each.
325
326
327       -I
328
329           Forgo device checks. This is used to generate a file image of  what
330           would go on a disk without using the device. Note that you must use
331           -S with this option (see above).
332
333
334       -n
335
336           Don't update fdisk table unless  explicitly  specified  by  another
337           option. If no other options are used, -n will only write the master
338           boot record to the disk. In addition, note that fdisk will not come
339           up in interactive mode if the -n option is specified.
340
341
342       -o offset
343
344           Block  offset  from  start of disk. This option is used for -P, -r,
345           and -w. Zero is assumed when this option is not used.
346
347
348       -P fill_patt
349
350           Fill disk with pattern fill_patt. fill_patt can be decimal  or  hex
351           and  is used as number for constant long word pattern. If fill_patt
352           is #, then pattern is block # for each block.  Pattern  is  put  in
353           each block as long words and fills each block (see -o and -s).
354
355
356       -r
357
358           Read  from  disk  and write to stdout. See -o and -s, which specify
359           the starting point and size of the operation.
360
361
362       -R
363
364           Treat disk as read-only. This is for testing purposes.
365
366
367       -s size
368
369           Number of blocks to perform operation on (see -o).
370
371
372       -S geom_file
373
374           Set the label  geometry  to  the  content  of  the  geom_file.  The
375           geom_file  contains  one specification line. Each line is delimited
376           by a new-line character (0fR). If the first character of a line  is
377           an  asterisk  (*),  the  line is treated as a comment. Each line is
378           composed of entries that are position-dependent, are  separated  by
379           white space, and have the following format:
380
381             pcyl ncyl acyl bcyl nheads nsectors sectsiz
382
383
384           where the entries have the following values:
385
386           pcyl        This is the number of physical cylinders for the drive.
387
388
389           ncyl        This is the number of usable cylinders for the drive.
390
391
392           acyl        This is the number of alt cylinders for the drive.
393
394
395           bcyl        This  is  the  number of offset cylinders for the drive
396                       (should be zero).
397
398
399           nheads      The number of heads for this drive.
400
401
402           nsectors    The number of sectors per track.
403
404
405           sectsiz     The size in bytes of a sector.
406
407
408
409       -t
410
411           Adjust incorrect slice table entries so that they  will  not  cross
412           partition table boundaries.
413
414
415       -T
416
417           Remove  incorrect  slice  table  entries  that span partition table
418           boundaries.
419
420
421       -v
422
423           Output the HBA (virtual) geometry dimensions. This option  must  be
424           used  in  conjunction  with  the -W flag. This option will work for
425           platforms which support virtual geometry. (x86 only)
426
427
428       -w
429
430           Write to disk and read from stdin. See -o and -s, which specify the
431           starting point and size of the operation.
432
433
434       -W −
435
436           Output the disk table to stdout.
437
438
439       -W fdisk_file
440
441           Create  an  fdisk file fdisk_file from disk table. This can be used
442           with the -F option below.
443
444

FILES

446       /dev/rdsk/c0t0d0p0       Raw device associated with the fixed disk.
447
448
449       /usr/lib/fs/ufs/mboot    Default master boot program.
450
451

ATTRIBUTES

453       See attributes(5) for descriptions of the following attributes:
454
455
456
457
458       ┌─────────────────────────────┬─────────────────────────────┐
459       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
460       ├─────────────────────────────┼─────────────────────────────┤
461       │Architecture                 │x86 and SPARC                │
462       ├─────────────────────────────┼─────────────────────────────┤
463       │Availability                 │SUNWcsu                      │
464       └─────────────────────────────┴─────────────────────────────┘
465

SEE ALSO

467       uname(1),    fmthard(1M),    format(1M),    newfs(1M),     prtvtoc(1M),
468       attributes(5)
469

DIAGNOSTICS

471       Most  messages will be self-explanatory. The following may appear imme‐
472       diately after starting the program:
473
474       Fdisk: cannot open <device>
475
476           This indicates that the device name argument is not valid.
477
478
479       Fdisk: unable to get device parameters for device <device>
480
481           This indicates a problem with the configuration of the fixed  disk,
482           or an error in the fixed disk driver.
483
484
485       Fdisk: error reading partition table
486
487           This  indicates  that  some error occurred when trying initially to
488           read the fixed disk. This could be a problem with  the  fixed  disk
489           controller or driver, or with the configuration of the fixed disk.
490
491
492       Fdisk: error writing boot record
493
494           This  indicates  that  some error occurred when trying to write the
495           new partition table out to the fixed disk. This could be a  problem
496           with the fixed disk controller, the disk itself, the driver, or the
497           configuration of the fixed disk.
498
499
500
501
502SunOS 5.11                        2 Jul 2009                         fdisk(1M)
Impressum