NAME
pdisk
—
Apple partition table editor
SYNOPSIS
pdisk |
[-acdfhilLrv ] [--abbr ]
[--compute_size ] [--debug ]
[--fname ] [--help ]
[--interactive ] [--list
device] [--logical ]
[--readonly ] [--version ]
[device ...] |
DESCRIPTION
pdisk
is a menu driven program which partitions disks
using the standard Apple disk partitioning scheme described in "Inside
Macintosh: Devices". It does not support the Intel/DOS partitioning
scheme supported by
fdisk(8).
Supported options are:
-a
--abbr
- Abbreviate the partition types shown in the partition list.
-c
--compute_size
- Causes
pdisk
to always ignore the device size listed in the partition table and compute the device size by other means. -d
--debug
- Turns on debugging. Doesn't add that much output, but does add a new command ‘x’ to the editing commands that accesses an eclectic bunch of undocumented functionality.
-f
--fname
- Show HFS volume names instead of partition name when available.
-h
--help
- Prints a short help message.
-i
--interactive
- Causes
pdisk
to go into an interactive mode similar to the MacOS version of the program. -l
--list
device- List the partition tables for the specified devices.
-L
--logical
- Show partition limits in logical blocks. Default is physical blocks.
-r
--readonly
- Prevents
pdisk
from writing to the device. -v
--version
- Prints the version number of
pdisk
.
Editing Partition Tables
An argument which is simply the name of a
device indicates that pdisk
should edit the partition table of that device.
The current top level editing commands are:
C (create with type also specified) c create new partition d delete a partition h command help i initialize partition map n (re)name a partition P (print ordered by base address) p print the partition table q quit editing (don't save changes) r reorder partition entry in map s change size of partition map t change the type of an existing partition w write the partition table
Commands which take arguments prompt for each argument in turn.
You can also type any number of the arguments separated by spaces and those
prompts will be skipped. The only exception to typeahead are the
confirmation prompts on the i
and
w
commands, since if we expect you to confirm the
decision, we shouldn't undermine that by allowing you to be precipitate
about it.
Partitions are always specified by their number, which is the index of the partition entry in the partition map. Most of the commands will change the index numbers of all partitions after the affected partition. You are advised to print the table as frequently as necessary.
The c
(create new partition) command is
the only one with complicated arguments. The first argument is the base
address (in blocks) of the partition. Besides a raw number, you can also
specify a partition number followed by the letter ‘p’ to
indicate that the first block of the new partition should be the same as the
first block of that existing free space partition. The second argument is
the length of the partition in blocks. This can be a raw number or can be a
partition number followed by the letter ‘p’ to use the size of
that partition or can be a number followed by ‘k’,
‘m’, or ‘g’ to indicate the size in kilobytes,
megabytes, or gigabytes respectively. (These are powers of 1024, of course,
not powers of 1000.) The third argument is the name of the partition. This
can be a single word without quotes, or a string surrounded by single or
double quotes. The type of the created partition will be Apple_UNIX_SVR2,
which is the correct type for use with NetBSD. This
command will prompt for the unix filesystem slice to set in the Block Zero
Block bits.
The C
command is similar to the
c
command, with the addition of a partition type
argument after the other arguments. Choosing a type of Apple_UNIX_SVR2 will
prompt for the unix filesystem slice to set in the Block Zero Block
bits.
The i
(initalize) command prompts for the
size of the device.
The n
(name) command allows the name of a
partition to be changed. Note that the various "Apple_Driver"
partitions depend on the name field for proper functioning. We are not aware
of any other partition types with this limitation.
The r
(reorder) command allows the index
number of partitions to be changed. The index numbers are constrained to be
a contiguous sequence.
The t
(change partition type) command
allows the type of a partition to be changed. Changing the type to
Apple_UNIX_SVR2 will prompt for the unix filesystem slice to set in the
Block Zero Block bits.
The w
(write) command writes the partition
map out. In order to use the new partition map you must reboot.
SEE ALSO
HISTORY
The pdisk
utility was originally developed
for MkLinux.
AUTHORS
Eryk Vershen
BUGS
Some people believe there should really be just one disk partitioning utility.
Filesystem volume names are out of place in a partition utility. This utility supports HFS volume names, but not volume names of any other filesystem types.
The --logical
option has not been heavily
tested.
pdisk
will first try to use
lseek(2) with SEEK_END
to compute the size of
the device. If this fails, it will try a binary search using
lseek(2) and
read(2) to find the end of the device. This has been observed to fail
on some raw disk devices. As a workaround, try using the block device
instead. pdisk
should probably read the disklabel
using the DIOCGDINFO
ioctl(2) to get the device size instead.