mpartition
Section: User Commands (1)
Updated: 28Nov20
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Name
mpartition - partition an MSDOS hard disk
Note of warning
This manpage has been automatically generated from mtools's texinfo
documentation, and may not be entirely accurate or complete. See the
end of this man page for details.
Description
The mpartition command is used to create MS-DOS file systems as
partitions. This is intended to be used on non-Linux systems,
i.e. systems where fdisk and easy access to SCSI devices are not
available. This command only works on drives whose partition variable
is set.
mpartition -p drive
mpartition -r drive
mpartition -I [-B bootSector] drive
mpartition -a drive
mpartition -d drive
mpartition -c [-s sectors] [-h heads]
[-t cylinders] [-v [-T type] [-b
begin] [-l length] [-f]
Mpartition supports the following operations:
- p
-
Prints a command line to recreate the partition for the drive. Nothing
is printed if the partition for the drive is not defined, or an
inconsistency has been detected. If verbose (-v) is also set,
prints the current partition table.
- r
-
Removes the partition described by drive.
- I
-
Initializes the partition table, and removes all partitions.
- c
-
Creates the partition described by drive.
- a
-
"Activates" the partition, i.e. makes it bootable. Only one partition
can be bootable at a time.
- d
-
"Deactivates" the partition, i.e. makes it unbootable.
If no operation is given, the current settings are printed.
For partition creations, the following options are available:
- s sectors
-
The number of sectors per track of the partition (which is also the
number of sectors per track for the whole drive).
- h heads
-
The number of heads of the partition (which is also the number of heads
for the whole drive). By default, the geometry information (number of
sectors and heads) is figured out from neighboring partition table
entries, or guessed from the size.
- t cylinders
-
The number of cylinders of the partition (not the number of cylinders of
the whole drive.
- b begin
-
The starting offset of the partition, expressed in sectors. If begin
is not given, mpartition lets the partition begin at the start
of the disk (partition number 1), or immediately after the end of the
previous partition.
- l length
-
The size (length) of the partition, expressed in sectors. If end is
not given, mpartition figures out the size from the number of
sectors, heads and cylinders. If these are not given either, it gives
the partition the biggest possible size, considering disk size and
start of the next partition.
The following option is available for all operation which modify the
partition table:
- f
-
Usually, before writing back any changes to the partition, mpartition
performs certain consistency checks, such as checking for overlaps and
proper alignment of the partitions. If any of these checks fails, the
partition table is not changed. The -f allows you to override
these safeguards.
The following options are available for all operations:
- v
-
Together with -p prints the partition table as it is now (no
change operation), or as it is after it is modified.
- vv
-
If the verbosity flag is given twice, mpartition will print out
a hexdump of the partition table when reading it from and writing it
to the device.
The following option is available for partition table initialization:
- B bootSector
-
Reads the template master boot record from file bootSector.
Choice of partition type
Mpartition proceeds as follows to pick a type for the partition:
- -
-
FAT32 partitions are assigned type 0x0C (``Win95 FAT32, LBA'')
- -
-
For all others, if the partition fits entirely within the first 65536
sectors of the disk, assign 0x01 (``DOS FAT12, CHS'') for FAT12
partition and 0x04 (``DOS FAT16, CHS'') for FAT16 partitions
- -
-
If not covered by the above, assign 0x06 (``DOS BIG FAT16 CHS'') if partition fits entirely within the first 1024 cylinders (CHS mode)
- -
-
All remaining cases get 0x0E (``Win95 BIG FAT16, LBA'')
If number of fat bits is not known (not specified in drive's
definition), then FAT12 is assumed for all drives with less than 4096
sectors, and FAT16 for those with more than 4096 sectors.
This corresponds more or less to the definitions outlined at https://en.wikipedia.org/wiki/Partition_type#List_of_partition_IDs
and
https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-2000-server/cc977219(v=technet.10),
with two notable differences:
- -
-
If fat bits are unknown, the reference documents consider drives with
less than 32680 sectors to be FAT12. Mtools uses 4096 sectors as the
cutoff point, as older versions of DOS only support FAT12 on disks
with less than 4096 sectors (and these older versions are the ones
which would be most likely to use FAT12 in the first place).
- -
-
The reference documents use a 8GB (wikipedia) or a 4GB (Microsoft)
cutoff between 0x06 (DOS BIG FAT16 CHS) and 0x0E. Mtools uses
1024 cylinders. This is because any partition beyond 1024 cylinders
must be LBA and cannot be CHS. 8GB works out to be the biggest
capacity which can be represented as CHS (63 sectors, 255 heads and
1024 cylinders). 4GB is the capacity limit for windows 2000, so it
makes sense that a documentation for windows 2000 would specify this
as the upper limit for any partition type.
See Also
Mtools' texinfo doc
Viewing the texi doc
This manpage has been automatically generated from mtools's texinfo
documentation. However, this process is only approximative, and some
items, such as crossreferences, footnotes and indices are lost in this
translation process. Indeed, these items have no appropriate
representation in the manpage format. Moreover, not all information has
been translated into the manpage version. Thus I strongly advise you to
use the original texinfo doc. See the end of this manpage for
instructions how to view the texinfo doc.
- *
-
To generate a printable copy from the texinfo doc, run the following
commands:
./configure; make dvi; dvips mtools.dvi
- *
-
To generate a html copy, run:
./configure; make html
A premade html can be found at
∞http://www.gnu.org/software/mtools/manual/mtools.htmlIntegral
- *
-
To generate an info copy (browsable using emacs' info mode), run:
./configure; make info
The texinfo doc looks most pretty when printed or as html. Indeed, in
the info version certain examples are difficult to read due to the
quoting conventions used in info.