FIXPARTS(8)							  FixParts Manual						       FIXPARTS(8)

NAME

       fixparts - MBR partition table repair utility

SYNOPSIS

       fixparts device

DESCRIPTION

       FixParts  (aka fixparts) is a text-mode menu-driven program for repairing certain types of problems with Master Boot Record (MBR) partition
       tables. The program has three design goals, although a few additional features are supported, as well:

       *      It can remove stray GUID Partition Table (GPT) data, which can be left behind on a disk that was once used as a GPT  disk  but  then
	      incompletely converted to the more common (as of 2011) MBR form.

       *      It  can  repair  mis-sized  extended partitions -- either partitions that extend beyond the physical end of the disk or that overlap
	      with nearby primary partitions. FixParts is designed in such a way that this type of repair occurs automatically,  so  if  it's  the
	      only problem with your disk, you can launch the program and then immediately save the partition table, making no manual changes, and
	      the program will fix the problem.

       *      You can change primary partitions into logical partitions or vice-versa, within constraints imposed by the MBR data structures.

       Additional features include the ability to change partition type codes or boot/active flags, to delete partitions,  and	to  recompute  CHS
       values.	With the possible exception of recomputing CHS values, these secondary features are better performed with fdisk, because fixpart's
       design means that it's likely to alter partition numbering even when such changes are not requested.

       The fixpart program employs a user interface similar to that of Linux's fdisk, but fixpart is much more specialized. Most importantly,  you
       can't create new partitions with fixpart, although you can change primary/logical assignment.

       In the MBR scheme, partitions come in three varieties:

       primary
	      These  partitions are defined in the first sector of the hard disk and are limited in number to four. Some OSes, such as Windows and
	      FreeBSD, must boot from a primary partition.

       extended
	      Extended partitions are specialized primary partitions. They serve as holding areas for logical partitions.

       logical
	      A disk can contain an arbitrary number of logical partitions (fixpart, however, imposes a limit of 124 logical partitions). All  the
	      logical  partitions  reside  inside a single extended partition, and are defined using a linked-list data structure. This fact means
	      that every logical partition be preceded by at least one sector of unallocated  space  to  hold  its  defining  data  structure  (an
	      Extended Boot Record, or EBR).

       These  distinctions  mean  that	primary and logical partitions cannot be arbitrarily interspersed. A disk can contain one to three primary
       partitions, a block of one or more logical partitions, and one to three more primary partitions (for a total of three  primary  partitions,
       not  counting the extended partition). Primary partitions may not be sandwiched between logical partitions, since this would mean placing a
       primary partition within an extended partition (which is just a specific type of primary partition).

       Unlike most disk utilities, fixpart's user interface ignores extended partitions. Internally, the program discards the information  on  the
       original  extended  partition  and, when you tell it to save its changes, it generates a new extended partition to contain the then-defined
       logical partitions. This is done because most of the repairs and manipulations the tool performs require generating a fresh extended parti-
       tion, so keeping the original in the user interface would only be a complication.

       Another	unusual feature of fixpart's user interface is that partition numbers do not necessarily correlate with primary/logical status. In
       most utilities, partitions 1-4 correspond to primary partitions, whereas partitions 5 and up are logical partitions. In fixpart, any parti-
       tion number may be assigned primary or logical status, so long as the rules for layout described earlier are obeyed. When the partition ta-
       ble is saved, partitions will be assigned appropriately and then tools such as the Linux kernel and fdisk will give them conventional  num-
       bers.

       When  it first starts, fixpart performs a scan for GPT data. If the disk looks like a conventional GPT disk, fixpart refuses to run. If the
       disk appears to be a conventional MBR disk but GPT signatures are present in the GPT primary or secondary header areas, fixpart	offers	to
       delete  this  extraneous  data.	If  you tell it to do so, the program immediately wipes the GPT header or headers. (If only one header was
       found, only that one header will be erased, to minimize the risk of damaging a boot loader or other data that might have  overwritten  just
       one of the GPT headers.)

       With  the exception of optionally erasing leftover GPT data when it first starts, fixpart keeps all changes in memory until the user writes
       changes with the w command. Thus, you can adjust your partitions in the user interface and abort those changes by typing q to quit  without
       saving changes.

OPTIONS

       The fixparts utility supports no command-line options, except for specification of the target device.

       Most interactions with fixparts occur with its interactive text-mode menu. Specific functions are:

       a      Toggle the active/boot flag. This flag is required by some boot loaders and OSes.

       c      Recompute the cylinder/head/sector (CHS) values for all partitions. CHS addressing mode is largely obsolete, but some OSes and util-
	      ities complain if they don't like the CHS values. Note that fixparts' CHS values are likely to be incorrect on  disks  smaller  than
	      about 8 GiB except on Linux.

       l      Change a partition's status to logical. This option will only work if the current partition layout supports such a change. Note that
	      if changing a partition's status in this way is not currently possible, making some other change may make it possible. For instance,
	      omitting	a partition that precedes the target partition may enable converting a partition to logical form if there had been no free
	      sectors between the two partitions.

       o      Omit a partition. Once omitted, the partition will still appear in the fixpart partition list, but it will be  flagged  as  omitted.
	      You  can	subsequently convert it to primary or logical form with the r or l commands, respectively. When you save your changes with
	      w, though, the partition will be lost.

       p      Display basic partition summary data. This includes partition's number, the boot/active flag's status, starting  and  ending  sector
	      numbers,	primary/logical/omitted  status,  whether  or  not the partition may be converted to logical form, and the partition's MBR
	      types code.

       q      Quit from the program without saving your changes.  Use this option if you just wanted to view information or if you make a  mistake
	      and want to back out of all your changes.

       r      Change a partition's status to primary. This option will only work if the current partition layout supports such a change. Note that
	      every partition can theoretically become a primary partition, although in some configurations, making this change will require omit-
	      ting  some  partitions.	If  fixparts refuses to allow changing a partition to primary, you may need to convert other partitions to
	      logical form or omit them entirely.

       s      Sort partition entries. This option orders partitions in the display to match their on-disk positions, which can make  understanding
	      the  disk  layout  easier  in some cases. This option has no effect on the ultimate ordering of logical partitions, which are sorted
	      before being saved. The order of primary partitions in the final saved partition table may be  affected  by  this  option.  In  both
	      cases, as already noted, the partition numbers displayed by fixparts may not be the same as those used by the kernel or displayed by
	      other partitioning tools.

       t      Change a partition's type code. You enter the type code using a one-byte hexadecimal number.

       w      Write data. Use this command to save your changes and exit from the program.

       ?      Print the menu. Type this command (or any other unrecognized command) to see a summary of available options.

BUGS

       As of May 2012 (version 0.8.5), fixparts should be considered beta software. Known bugs and limitations include:

       *      The program compiles correctly only on Linux, FreeBSD, Mac OS X, and Windows.  Linux versions for x86-64 (64-bit), x86 (32-bit), and
	      PowerPC  (32-bit)  have  been  tested,  with the x86-64 version having seen the most testing. Under FreeBSD, 32-bit (x86) and 64-bit
	      (x86-64) versions have been tested. Only 32-bit versions for Mac OS X and Windows have been tested.

       *      The FreeBSD version of the program can't write changes to the partition table to a disk when existing partitions on  that  disk  are
	      mounted. (The same problem exists with many other FreeBSD utilities, such as gpt, fdisk, and dd.) This limitation can be overcome by
	      typing sysctl kern.geom.debugflags=16 at a shell prompt.

       *      The program can load only up to 128 partitions (4 primary partitions and 124 logical partitions). This limit can be raised by chang-
	      ing the #define MAX_MBR_PARTS line in the basicmbr.h source code file and recompiling.

       *      The  program  can read partitions only if the disk has correct LBA partition descriptors. These descriptors should be present on any
	      disk over 8 GiB in size or on smaller disks partitioned with any but very ancient software.

       *      The program makes no effort to preserve partition numbers. This can have consequences for boot loaders and for mounting  filesystems
	      via /etc/fstab. It may be necessary to edit configuration files or even to re-install your boot loader.

       *

	      The program may change the order of partitions in the partition table.

AUTHORS

       Primary author: Roderick W. Smith (rodsmith@rodsbooks.com)

       Contributors:

       * Yves Blusseau (1otnwmz02@sneakemail.com)

       * David Hubbard (david.c.hubbard@gmail.com)

       * Justin Maggard (justin.maggard@netgear.com)

       * Dwight Schauer (dschauer@ti.com)

       * Florian Zumbiehl (florz@florz.de)

SEE ALSO

       cfdisk (8), cgdisk (8), fdisk (8), mkfs (8), parted (8), sfdisk (8) gdisk (8) sgdisk (8)

       http://en.wikipedia.org/wiki/Master_boot_record

       http://www.rodsbooks.com/fixparts/

AVAILABILITY

       The fixparts command is part of the GPT fdisk package and is available from Rod Smith.

Roderick W. Smith						       0.8.5							       FIXPARTS(8)