fixparts.8 - platform/external/gptfdisk - Gitiles

 .\" Copyright 2011-2013 Roderick W. Smith (rodsmith@rodsbooks.com)
 .\" May be distributed under the GNU General Public License
 .TH "FIXPARTS" "8" "0.8.10" "Roderick W. Smith" "FixParts Manual"
 .SH "NAME"
 fixparts \- MBR partition table repair utility
 .SH "SYNOPSIS"
 .BI "fixparts "
 .I device

 .SH "DESCRIPTION"

 FixParts (aka \fBfixparts\fR) 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:

 .TP
 .B *
 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.

 .TP
 .B *
 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.

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

 .PP

 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 \fBfdisk\fR, because \fBfixparts\fR' design means
 that it's likely to alter partition numbering even when such changes are
 not requested.

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

 In the MBR scheme, partitions come in three varieties:

 .TP
 .B 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.

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

 .TP
 .B logical
 A disk can contain an arbitrary number of logical partitions
 (\fBfixparts\fR, 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 must be preceded by at least one sector of unallocated space
 to hold its defining data structure (an Extended Boot Record, or EBR).

 .PP

 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, \fBfixparts\fR' 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 partition, so keeping the
 original in the user interface would only be a complication.

 Another unusual feature of \fBfixparts\fR' 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 \fBfixparts\fR, any partition
 number may be assigned primary or logical status, so long as the rules for
 layout described earlier are obeyed. When the partition table is saved,
 partitions will be assigned appropriately and then tools such as the Linux
 kernel and \fBfdisk\fR will give them conventional numbers.

 When it first starts, \fBfixparts\fR performs a scan for GPT data. If the
 disk looks like a conventional GPT disk, \fBfixparts\fR 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, \fBfixparts\fR
 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, \fBfixparts\fR keeps all changes in memory until the user writes
 changes with the \fBw\fR command. Thus, you can adjust your partitions in
 the user interface and abort those changes by typing \fBq\fR to quit
 without saving changes.

 .SH "OPTIONS"

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

 Most interactions with \fBfixparts\fR occur with its interactive text\-mode
 menu. Specific functions are:

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


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

 .TP
 .B 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.

 .TP
 .B o
 Omit a partition. Once omitted, the partition will still appear in the
 \fBfixparts\fR partition list, but it will be flagged as omitted. You can
 subsequently convert it to primary or logical form with the \fBr\fR or
 \fBl\fR commands, respectively. When you save your changes with \fBw\fR,
 though, the partition will be lost.

 .TP
 .B 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.

 .TP
 .B q
 Quit from the program \fIwithout saving your changes\fR.
 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.

 .TP
 .B 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 omitting some partitions.
 If \fBfixparts\fR refuses to allow changing a partition to primary, you may
 need to convert other partitions to logical form or omit them entirely.

 .TP
 .B 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 \fBfixparts\fR may not be the same as those used by the kernel
 or displayed by other partitioning tools.

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

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

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

 .PP

 .SH "BUGS"
 As of March 2014 (version 0.8.10), \fBfixparts\fR
 should be considered beta software. Known bugs and limitations include:

 .TP
 .B *
 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.

 .TP
 .B *
 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
 \fBgpt\fR, \fBfdisk\fR, and \fBdd\fR.) This limitation can be overcome
 by typing \fBsysctl kern.geom.debugflags=16\fR at a shell prompt.

 .TP
 .B *
 The program can load only up to 128 partitions (4 primary partitions and
 124 logical partitions). This limit can be raised by changing the
 \fI#define MAX_MBR_PARTS\fR line in the \fIbasicmbr.h\fR source code file
 and recompiling.

 .TP
 .B *
 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.

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

 .TP
 .B *

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

 .PP

 .SH "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)


 .SH "SEE ALSO"
 \fBcfdisk (8)\fR,
 \fBcgdisk (8)\fR,
 \fBfdisk (8)\fR,
 \fBmkfs (8)\fR,
 \fBparted (8)\fR,
 \fBsfdisk (8)\fR
 \fBgdisk (8)\fR
 \fBsgdisk (8)\fR

 \fIhttp://en.wikipedia.org/wiki/Master_boot_record\fR

 \fIhttp://www.rodsbooks.com/fixparts/\fR

 .SH "AVAILABILITY"
 The \fBfixparts\fR command is part of the \fIGPT fdisk\fR package and is
 available from Rod Smith.
	.\" Copyright 2011-2013 Roderick W. Smith (rodsmith@rodsbooks.com)
	.\" May be distributed under the GNU General Public License
	.TH "FIXPARTS" "8" "0.8.10" "Roderick W. Smith" "FixParts Manual"
	.SH "NAME"
	fixparts \- MBR partition table repair utility
	.SH "SYNOPSIS"
	.BI "fixparts "
	.I device

	.SH "DESCRIPTION"

	FixParts (aka \fBfixparts\fR) 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:

	.TP
	.B *
	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.

	.TP
	.B *
	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.

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

	.PP

	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 \fBfdisk\fR, because \fBfixparts\fR' design means
	that it's likely to alter partition numbering even when such changes are
	not requested.

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

	In the MBR scheme, partitions come in three varieties:

	.TP
	.B 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.

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

	.TP
	.B logical
	A disk can contain an arbitrary number of logical partitions
	(\fBfixparts\fR, 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 must be preceded by at least one sector of unallocated space
	to hold its defining data structure (an Extended Boot Record, or EBR).

	.PP

	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, \fBfixparts\fR' 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 partition, so keeping the
	original in the user interface would only be a complication.

	Another unusual feature of \fBfixparts\fR' 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 \fBfixparts\fR, any partition
	number may be assigned primary or logical status, so long as the rules for
	layout described earlier are obeyed. When the partition table is saved,
	partitions will be assigned appropriately and then tools such as the Linux
	kernel and \fBfdisk\fR will give them conventional numbers.

	When it first starts, \fBfixparts\fR performs a scan for GPT data. If the
	disk looks like a conventional GPT disk, \fBfixparts\fR 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, \fBfixparts\fR
	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, \fBfixparts\fR keeps all changes in memory until the user writes
	changes with the \fBw\fR command. Thus, you can adjust your partitions in
	the user interface and abort those changes by typing \fBq\fR to quit
	without saving changes.

	.SH "OPTIONS"

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

	Most interactions with \fBfixparts\fR occur with its interactive text\-mode
	menu. Specific functions are:

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


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

	.TP
	.B 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.

	.TP
	.B o
	Omit a partition. Once omitted, the partition will still appear in the
	\fBfixparts\fR partition list, but it will be flagged as omitted. You can
	subsequently convert it to primary or logical form with the \fBr\fR or
	\fBl\fR commands, respectively. When you save your changes with \fBw\fR,
	though, the partition will be lost.

	.TP
	.B 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.

	.TP
	.B q
	Quit from the program \fIwithout saving your changes\fR.
	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.

	.TP
	.B 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 omitting some partitions.
	If \fBfixparts\fR refuses to allow changing a partition to primary, you may
	need to convert other partitions to logical form or omit them entirely.

	.TP
	.B 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 \fBfixparts\fR may not be the same as those used by the kernel
	or displayed by other partitioning tools.

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

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

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

	.PP

	.SH "BUGS"
	As of March 2014 (version 0.8.10), \fBfixparts\fR
	should be considered beta software. Known bugs and limitations include:

	.TP
	.B *
	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.

	.TP
	.B *
	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
	\fBgpt\fR, \fBfdisk\fR, and \fBdd\fR.) This limitation can be overcome
	by typing \fBsysctl kern.geom.debugflags=16\fR at a shell prompt.

	.TP
	.B *
	The program can load only up to 128 partitions (4 primary partitions and
	124 logical partitions). This limit can be raised by changing the
	\fI#define MAX_MBR_PARTS\fR line in the \fIbasicmbr.h\fR source code file
	and recompiling.

	.TP
	.B *
	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.

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

	.TP
	.B *

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

	.PP

	.SH "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)


	.SH "SEE ALSO"
	\fBcfdisk (8)\fR,
	\fBcgdisk (8)\fR,
	\fBfdisk (8)\fR,
	\fBmkfs (8)\fR,
	\fBparted (8)\fR,
	\fBsfdisk (8)\fR
	\fBgdisk (8)\fR
	\fBsgdisk (8)\fR

	\fIhttp://en.wikipedia.org/wiki/Master_boot_record\fR

	\fIhttp://www.rodsbooks.com/fixparts/\fR

	.SH "AVAILABILITY"
	The \fBfixparts\fR command is part of the \fIGPT fdisk\fR package and is
	available from Rod Smith.