MAC-FDISK(8) Linux Programmer's Manual MAC-FDISK(8)
NAME
mac-fdisk - Apple partition table editor for Linux
SYNOPSIS
mac-fdisk [-h|--help] [-v|--version] [-l|--list [name
...]]
mac-fdisk [-r|--readonly] device ...
DESCRIPTION
mac-fdisk 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. The device is usually one of the following:
/dev/sda
/dev/sdb
/dev/sdc
/dev/sdd
/dev/sde
/dev/sdf
/dev/sdg
/dev/hda
/dev/hdb
MkLinux interprets device names differently than standard
Linux. In MkLinux /dev/sda is the device at SCSI id 0,
/dev/sdb is the device at SCSI id 1, and so on. In stan
dard Linux /dev/sda is the first hard disk on the SCSI bus
(i.e. the one with the lowest id), /dev/sdb is the second
hard disk, and so on. The partition is a device name fol
lowed by a partition number. The partition number is the
index (starting from one) of the partition map entry in
the partition map. For example, /dev/sda2 is the parti
tion described by the second entry in the partiton map on
/dev/sda.
OPTIONS
-v | --version
Prints version number of the mac-fdisk program.
-h | --help
Prints a rather lame set of help messages for the
mac-fdisk program.
-l | --list
If no names are present then lists the partition
tables for /dev/sda, /dev/sdb, /dev/sdc, /dev/sdd,
/dev/sde, /dev/sdf, and /dev/sdg. Otherwise, lists
the partition tables for the specified names.
-r | --readonly
Prevents mac-fdisk from writing to the device.
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Editing Partition Tables
An argument which is simply the name of a device indicates
that mac-fdisk should edit the partition table of that
device.
The current top level editing commands are:
h command help
p print the partition table
P (print ordered by base address)
i initialize partition map
s change size of partition map
c create new partition
C (create with type also specified)
d delete a partition
r reorder partition entry in map
w write the partition table
q quit without saving changes
Commands which take arguments prompt for each argument in
turn. You can also type any number of the arguments sepa
rated by spaces and those prompts will be skipped. The
only exception to typeahead are the confirmation prompts
on the i and w commands. The idea being that 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 the
index of the partition entry in the partition map. Most
of the commands will change the index numbers of all par
titions after the affected partition. You are advised to
print the table as frequently as necessary.
Creating more than fifteen partitions is not advised.
There is currently a bug in the some (all?) of the kernels
which causes access to the whole disk fail if more than
fifteen partitions are in the map.
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 num
ber, 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 kilo
bytes, megabytes, or gigabytes respectively. (These are
powers of 1024, of course, not powers of 1000.) The last
argument is the name of the partition. This can be a sin
gle word without quotes, or a string surrounded by single
or double quotes.
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The C command is identical to the c command, with the
addition of a partition type argument after the other
arguments. The partition type used for Linux swap and data
partitons is APPLE_UNIX_SVR2 (this partition type is set
by the c command automatically when the partition name is
one of the typical A/UX partition names as root&usr, root,
usr or swap). Under normal circumstances, you should not
need to use this command.
The r (reorder) command allows the index number of parti
tions to be changed. The index numbers are constrained to
be a contiguous sequence.
The i (initalize) command prompts for the size of the
device. This was done to get around a bug in the kernel
where it reports the wrong size for the device.
The w (write) command does write the partition map out,
but there is currently a bug in the interaction between
MkLinux and Mach which causes the partition map not to be
reinterpreted. In order to use the new partition map you
must reboot.
BUGS
Some people believe there should really be just one disk
partitioning utility.
mac-fdisk should be able to create HFS partitions that
work. Currently, if a pre-existing HFS partition is
resized, MacOS will continue to use the partition size
stored in the HFS 'superblock' instead of using the size
from the partition table (the MacOS volume on the parti
tion remains valid even though the sizes don't match any
more). This can have undesired side effects especially
when creating a few Linux partitions in part of the previ
ous HFS partition space. In order for MacOS to reinitial
ize the volume, the HFS partition needs to be invalidated
by zeroing the first few megs with dd.
Even more help should be available during user input.
SEE ALSO
fdisk(8), mkswap(8), mkfs(8)
AUTHOR
Eryk Vershen (eryk@apple.com)
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