fdisk(1M)						  System Administration Commands						 fdisk(1M)

NAME

       fdisk - create or modify fixed disk partition table

SYNOPSIS

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

DESCRIPTION

       This command is used to do the following:

	 o  Create and modify an fdisk partition table on x86 systems

	 o  Create and modify an fdisk partition table on removable media on SPARC or x86 systems

	 o  Install the master boot record that is put in the first sector of the fixed disk on x86 systems only

       This  table  is used by the first-stage bootstrap (or firmware) to identify parts of the disk reserved for different operating systems, and
       to identify the partition containing the second-stage bootstrap (the active Solaris partition). The rdevice argument must be used to  spec-
       ify the raw device associated with the fixed disk, for example, /dev/rdsk/c0t0d0p0.

       The  program  can  operate in three different modes. The first is interactive mode. In interactive mode, the program displays the partition
       table as it exists on the disk, and then presents a menu allowing the user to modify the table. The menu, questions,  warnings,	and  error
       messages are intended to be self-explanatory.

       In interactive mode, if there is no partition table on the disk, the user is given the options of creating a default partitioning or speci-
       fying the initial table values. The default partitioning allocates the entire disk for the Solaris system and makes the Solaris system par-
       tition  active.	In  either  case, when the initial table is created, fdisk also writes out the first-stage bootstrap (x86 only) code along
       with the partition table.

       The second mode of operation is used for automated entry addition, entry deletion, or replacement of the entire fdisk table. This mode  can
       add or delete an entry described on the command line. In this mode the entire fdisk table can be read in from a file replacing the original
       table. fdisk can also be used to create this file. There is a command line option that will cause fdisk to replace any fdisk table with the
       default of the whole disk for the Solaris system.

       The  third mode of operation is used for disk diagnostics. In this mode, a section of the disk can be filled with a user specified pattern,
       and mode sections of the disk can also be read or written.

   Menu Options
       The menu options for interactive mode given by the fdisk program are:

       Create a partition

	   This option allows the user to create a new partition. The maximum number of partitions is 4. The program will ask for the type of  the
	   partition  (SOLARIS,  MS-DOS, UNIX, or other). It will then ask for the size of the partition as a percentage of the disk. The user may
	   also enter the letter c at this point, in which case the program will ask for the starting cylinder number and size of the partition in
	   cylinders. If a c is not entered, the program will determine the starting cylinder number where the partition will fit. In either case,
	   if the partition would overlap an existing partition or will not fit, a message is displayed and the program returns  to  the  original
	   menu.

       Change Active (Boot from) partition

	   This  option  allows the user to specify the partition where the first-stage bootstrap will look for the second-stage bootstrap, other-
	   wise known as the active partition.

       Delete a partition

	   This option allows the user to delete a previously created partition. Note that this will destroy all data in that partition.

       Change between Solaris and Solaris2 Partition IDs

	   This option allows the user to switch between the current fdisk operating system partition identifier and the previous one.	This  does
	   not affect any data in the disk partition and is provided for compatibility with older software.

       Use  the following options to include your modifications to the partition table at this time or to cancel the session without modifying the
       table:

       Exit

	   This option writes the new version of the table created during this session with fdisk out to the fixed disk, and exits the program.

       Cancel

	   This option exits without modifying the partition table.

OPTIONS

       The following options apply to fdisk:

       -A id:act:bhead:bsect:bcyl:ehead:esect:ecyl:rsect:numsect

	   Add a partition as described by the argument (see the -F option below for the format). Use of this option will zero out the
	    VTOC on the Solaris partition if the fdisk table changes.

       -b master_boot

	   Specify the file master_boot as the master boot program. The default master boot program is /usr/lib/fs/ufs/mboot.

       -B

	   Default to one Solaris partition that uses the whole disk.

       -d

	   Turn on verbose debug mode. This will cause fdisk to print its state on stderr as it is used. The output from this option should not be
	   used with -F.

       -D id:act:bhead:bsect:bcyl:ehead:esect:ecyl:rsect:numsect

	   Delete a partition as described by the argument (see the -F option below for the format). Note that the argument must be an exact match
	   or the entry will not be deleted! Use of this option will zero out the VTOC on the Solaris partition if the fdisk table changes.

       -E

	   Create an EFI partition that uses the entire disk.

       -F fdisk_file

	   Use fdisk file fdisk_file to initialize table. Use of this option will zero out the VTOC on the Solaris partition if  the  fdisk  table
	   changes.

	   The fdisk_file contains up to four specification lines. Each line is delimited by a new-line character(0fR). If the first character of
	   a line is an asterisk (*), the line is treated as a comment. Each line is composed of entries that are  position-dependent,	are  sepa-
	   rated by ``white space'' or colons, and have the following format:

	   id act bhead bsect bcyl ehead esect ecyl rsect numsect

	   where the entries have the following values:

	   id		   This is the type of partition and the correct numeric values may be found in fdisk.h.

	   act		   This is the active partition flag; 0 means not active and 128 means active.

	   bhead	   This is the head where the partition starts. If this is set to 0, fdisk will correctly fill this in from other informa-
			   tion.

	   bsect	   This is the sector where the partition starts. If this is set to 0, fdisk will correctly fill this in from other infor-
			   mation.

	   bcyl 	   This  is  the  cylinder  where  the partition starts. If this is set to 0, fdisk will correctly fill this in from other
			   information.

	   ehead	   This is the head where the partition ends. If this is set to 0, fdisk will correctly fill this in from  other  informa-
			   tion.

	   esect	   This is the sector where the partition ends. If this is set to 0, fdisk will correctly fill this in from other informa-
			   tion.

	   ecyl 	   This is the cylinder where the partition ends. If this is set to 0, fdisk will correctly fill this in from other infor-
			   mation.

	   rsect	   The	relative  sector from the beginning of the disk where the partition starts. This must be specified and can be used
			   by fdisk to fill in other fields.

	   numsect	   The size in sectors of this disk partition. This must be specified and can be used by fdisk to fill in other fields.

       -g

	   Get the label geometry for disk and display on stdout (see the -S option for the format).

       -G

	   Get the physical geometry for disk and display on stdout (see the -S option for the format).

       -h

	   Issue verbose message; message will list all options and supply an explanation for each.

       -I

	   Forgo device checks. This is used to generate a file image of what would go on a disk without using the device. Note that you must  use
	   -S with this option (see above).

       -n

	   Don't  update  fdisk  table	unless explicitly specified by another option. If no other options are used, -n will only write the master
	   boot record to the disk. In addition, note that fdisk will not come up in interactive mode if the -n option is specified.

       -o offset

	   Block offset from start of disk. This option is used for -P, -r, and -w. Zero is assumed when this option is not used.

       -P fill_patt

	   Fill disk with pattern fill_patt. fill_patt can be decimal or hex and is used as number for constant long word pattern. If fill_patt is
	   #, then pattern is block # for each block. Pattern is put in each block as long words and fills each block (see -o and -s).

       -r

	   Read from disk and write to stdout. See -o and -s, which specify the starting point and size of the operation.

       -R

	   Treat disk as read-only. This is for testing purposes.

       -s size

	   Number of blocks to perform operation on (see -o).

       -S geom_file

	   Set the label geometry to the content of the geom_file. The geom_file contains one specification line. Each line is delimited by a new-
	   line character(0fR). If the first character of a line is an asterisk (*), the line is treated as a comment. Each line is  composed	of
	   entries that are position-dependent, are separated by white space, and have the following format:

	   pcyl ncyl acyl bcyl nheads nsectors sectsiz

	   where the entries have the following values:

	   pcyl 	   This is the number of physical cylinders for the drive.

	   ncyl 	   This is the number of usable cylinders for the drive.

	   acyl 	   This is the number of alt cylinders for the drive.

	   bcyl 	   This is the number of offset cylinders for the drive (should be zero).

	   nheads	   The number of heads for this drive.

	   nsectors	   The number of sectors per track.

	   sectsiz	   The size in bytes of a sector.

       -t

	   Adjust incorrect slice table entries so that they will not cross partition table boundaries.

       -T

	   Remove incorrect slice table entries that span partition table boundaries.

       -v

	   Output the HBA (virtual) geometry dimensions. This option must be used in conjunction with the -W flag. This option will work for plat-
	   forms which support virtual geometry. (x86 only)

       -w

	   Write to disk and read from stdin. See -o and -s, which specify the starting point and size of the operation.

       -W -

	   Output the disk table to stdout.

       -W fdisk_file

	   Create an fdisk file fdisk_file from disk table. This can be used with the -F option below.

FILES

       /dev/rdsk/c0t0d0p0      Raw device associated with the fixed disk.

       /usr/lib/fs/ufs/mboot   Default master boot program.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Architecture		     |x86 and SPARC		   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsu			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       uname(1), fmthard(1M), prtvtoc(1M), attributes(5)

DIAGNOSTICS

       Most messages will be self-explanatory. The following may appear immediately after starting the program:

       Fdisk: cannot open <device>

	   This indicates that the device name argument is not valid.

       Fdisk: unable to get device parameters for device <device>

	   This indicates a problem with the configuration of the fixed disk, or an error in the fixed disk driver.

       Fdisk: error reading partition table

	   This indicates that some error occurred when trying initially to read the fixed disk. This could be a problem with the fixed disk  con-
	   troller or driver, or with the configuration of the fixed disk.

       Fdisk: error writing boot record

	   This  indicates  that  some	error occurred when trying to write the new partition table out to the fixed disk. This could be a problem
	   with the fixed disk controller, the disk itself, the driver, or the configuration of the fixed disk.

SunOS 5.10							    19 Nov 2004 							 fdisk(1M)