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GDISK(8)		       GPT fdisk Manual			      GDISK(8)

       gdisk - Interactive GUID partition table (GPT) manipulator

       gdisk [ -l ] device

       GPT  fdisk  (aka gdisk) is a text-mode menu-driven program for creation
       and manipulation of partition tables. It will automatically convert  an
       old-style  Master  Boot	Record	(MBR) partition table or BSD disklabel
       stored without an MBR carrier partition to the  newer  Globally	Unique
       Identifier  (GUID)  Partition  Table  (GPT) format, or will load a GUID
       partition table. When used with the -l command-line option, the program
       displays the current partition table and then exits.

       GPT fdisk operates mainly on the GPT headers and partition tables; how‐
       ever, it can and will generate a fresh protective MBR,  when  required.
       (Any  boot loader code in the protective MBR will not be disturbed.) If
       you've created an unusual protective MBR, such as a hybrid MBR  created
       by  gptsync or gdisk's own hybrid MBR creation feature, this should not
       be disturbed by most ordinary  actions.	Some  advanced	data  recovery
       options require you to understand the distinctions between the main and
       backup data, as well as between	the  GPT  headers  and	the  partition
       tables.	For information on MBR vs. GPT, as well as GPT terminology and
       structure, see the extended  gdisk  documentation  at  http://www.rods‐ or consult Wikipedia.

       The  gdisk  program employs a user interface similar to that of Linux's
       fdisk, but gdisk modifies GPT partitions. It also has the capability of
       transforming MBR partitions or BSD disklabels into GPT partitions. Like
       the original fdisk program, gdisk does not modify disk structures until
       you  explicitly	write  them to disk, so if you make a mistake, you can
       exit from the program with the 'q'  option  to  leave  your  partitions

       Ordinarily,  gdisk  operates  on disk device files, such as /dev/sda or
       /dev/hda under Linux,  /dev/disk0  under	 Mac  OS  X,  or  /dev/ad0  or
       /dev/da0	 under	FreeBSD.  The  program	can also operate on disk image
       files, which can be either copies of whole disks	 (made	with  dd,  for
       instance)  or raw disk images used by emulators such as QEMU or VMWare.
       Note that only raw disk images are supported; gdisk cannot work on com‐
       pressed or other advanced disk image formats.

       The  MBR partitioning system uses a combination of cylinder/head/sector
       (CHS) addressing and logical block  addressing  (LBA).  The  former  is
       klunky  and limiting. GPT drops CHS addressing and uses 64-bit LBA mode
       exclusively. Thus, GPT data structures, and  therefore  gdisk,  do  not
       need  to	 deal  with  CHS  geometries and all the problems they create.
       Users of fdisk will note that gdisk lacks the options  and  limitations
       associated with CHS geometries.

       For best results, you should use an OS-specific partition table program
       whenever possible. For example, you should make	Mac  OS	 X  partitions
       with  the  Mac  OS X Disk Utility program and Linux partitions with the
       Linux gdisk or GNU Parted program.

       Upon start, gdisk attempts to identify the partition type in use on the
       disk.  If  it finds valid GPT data, gdisk will use it. If gdisk finds a
       valid MBR or BSD disklabel but no GPT data, it will attempt to  convert
       the  MBR or disklabel into GPT form. (BSD disklabels are likely to have
       unusable first and/or final partitions because they  overlap  with  the
       GPT  data structures, though.) GPT fdisk can identify, but not use data
       in, Apple Partition Map (APM) disks, which are used on 680x0- and  Pow‐
       erPC-based  Macintoshes.	 Upon  exiting	with  the  'w'	option,	 gdisk
       replaces the MBR or disklabel with a GPT. This  action  is  potentially
       dangerous!  Your system may become unbootable, and partition type codes
       may become corrupted if the disk uses  unrecognized  type  codes.  Boot
       problems	 are  particularly  likely  if	you're	multi-booting with any
       GPT-unaware OS. If you mistakenly launch gdisk on an MBR disk, you  can
       safely  exit  the  program  without making any changes by using the 'q'

       The MBR-to-GPT conversion will leave at least one gap in the  partition
       numbering  if  the original MBR used logical partitions. These gaps are
       harmless, but you can eliminate them by using the 's'  option,  if  you
       like.  (Doing this may require you to update your /etc/fstab file.)

       When creating a fresh partition table, certain considerations may be in

       *      For data (non-boot) disks, and for boot disks used on BIOS-based
	      computers	 with  GRUB as the boot loader, partitions may be cre‐
	      ated in whatever order and in whatever sizes are desired.

       *      Boot disks for EFI-based systems require an EFI System Partition
	      (gdisk  internal	code  0xEF00) formatted as FAT-32.  The recom‐
	      mended size of this  partition  is  between  100	and  300  MiB.
	      Boot-related  files are stored here. (Note that GNU Parted iden‐
	      tifies such partitions as having the "boot flag" set.)

       *      Some boot loaders for BIOS-based systems make use of a BIOS Boot
	      Partition	 (gdisk	 internal code 0xEF02), in which the secondary
	      boot loader  is  stored,	possibly  without  the	benefit	 of  a
	      filesystem.  (GRUB2  may	optionally use such a partition.) This
	      partition can typically be quite small (roughly 32 to 200	 KiB),
	      but  you	should	consult	 your  boot  loader  documentation for

       *      If Windows is to boot from a GPT disk, a partition of  type  Mi‐
	      crosoft  Reserved	 (gdisk	 internal code 0x0C01) is recommended.
	      This partition should be about 128 MiB in	 size.	It  ordinarily
	      follows  the  EFI	 System Partition and immediately precedes the
	      Windows data partitions. (Note that old versions of  GNU	Parted
	      create all FAT partitions as this type, which actually makes the
	      partition unusable for normal file storage in both  Windows  and
	      Mac OS X.)

       *      Some  OSes' GPT utilities create some blank space (typically 128
	      MiB) after each partition. The intent is to enable  future  disk
	      utilities	 to use this space. Such free space is not required of
	      GPT disks, but creating it may help in future disk  maintenance.
	      You  can	use  GPT fdisk's relative partition positioning option
	      (specifying the starting sector as  '+128M',  for	 instance)  to
	      simplify creating such gaps.

       -l     List  the	 partition  table  for	the  specified device and then

       Most interactions with  gdisk  occur  with  its	interactive  text-mode
       menus.  Three menus exist: the main menu, the recovery & transformation
       menu, and the experts' menu. The main menu provides the functions  that
       are  most  likely  to be useful for typical partitioning tasks, such as
       creating and deleting partitions, changing partition type codes, and so
       on. Specific functions are:

       b      Save  partition data to a backup file. You can back up your cur‐
	      rent in-memory partition table to a disk file using this option.
	      The resulting file is a binary file consisting of the protective
	      MBR, the main GPT header, the backup GPT header, and one copy of
	      the  partition  table, in that order. Note that the backup is of
	      the current in-memory data structures, so if you launch the pro‐
	      gram,  make  changes,  and then use this option, the backup will
	      reflect your changes. Note also that the restore	option	is  on
	      the  recovery & transformation menu; the backup option is on the
	      main menu to encourage its use.

       c      Change the GPT name of a partition. This name is	encoded	 as  a
	      UTF-16  string,  but proper entry and display of anything beyond
	      basic ASCII values requires suitable locale  and	font  support.
	      For  the most part, Linux ignores the partition name, but it may
	      be important in some OSes. GPT fdisk sets a default  name	 based
	      on  the partition type code. Note that the GPT partition name is
	      different from the filesystem name,  which  is  encoded  in  the
	      filesystem's data structures.

       d      Delete  a partition. This action deletes the entry from the par‐
	      tition table but does not disturb the data  within  the  sectors
	      originally  allocated  to the partition on the disk. If a corre‐
	      sponding hybrid MBR partition exists, gdisk deletes it, as well,
	      and expands any adjacent 0xEE (EFI GPT) MBR protective partition
	      to fill the new free space.

       i      Show detailed partition  information.  The  summary  information
	      produced by the 'p' command necessarily omits many details, such
	      as the partition's unique GUID and the  translation  of  gdisk's
	      internal	partition  type	 code  to  a  plain type name. The 'i'
	      option displays this information for a single partition.

       l      Display a summary of partition types. GPT uses a GUID  to	 iden‐
	      tify  partition types for particular OSes and purposes. For ease
	      of data entry, gdisk compresses these into two-byte  (four-digit
	      hexadecimal)  values  that  are  related to their equivalent MBR
	      codes. Specifically, the MBR code is multiplied  by  hexadecimal
	      0x0100.  For  instance,  the code for Linux swap space in MBR is
	      0x82, and it's 0x8200 in gdisk. A one-to-one  correspondence  is
	      impossible, though. Most notably, the codes for all varieties of
	      FAT and NTFS partition correspond to a single GPT code  (entered
	      as 0x0700 in sgdisk). Some OSes use a single MBR code but employ
	      many more codes in GPT.  For  these,  gdisk  adds	 code  numbers
	      sequentially, such as 0xa500 for a FreeBSD disklabel, 0xa501 for
	      FreeBSD boot, 0xa502 for FreeBSD swap,  and  so  on.  Note  that
	      these two-byte codes are unique to gdisk.

       n      Create  a	 new  partition.  This	command	 is modelled after the
	      equivalent fdisk option, although some  differences  exist.  You
	      enter a partition number, starting sector, and an ending sector.
	      Both start and end sectors can be specified in absolute terms as
	      sector  numbers  or  as  positions  measured  in	kibibytes (K),
	      mebibytes (M), gibibytes (G), tebibytes (T), or  pebibytes  (P);
	      for  instance,  40M specifies a position 40MiB from the start of
	      the disk. You can specify locations relative to the start or end
	      of  the specified default range by preceding the number by a '+'
	      or '-' symbol, as in +2G to  specify  a  point  2GiB  after  the
	      default  start sector, or -200M to specify a point 200MiB before
	      the last available sector. Pressing the Enter key with no	 input
	      specifies	 the  default value, which is the start of the largest
	      available block for the start sector and the  end	 of  the  same
	      block for the end sector.

       o      Clear out all partition data. This includes GPT header data, all
	      partition definitions, and the protective MBR. The sector align‐
	      ment is reset to the default (2048 sectors, or 1MB).

       p      Display  basic  partition	 summary data. This includes partition
	      numbers, starting and ending sector  numbers,  partition	sizes,
	      gdisk's  partition  types	 codes, and partition names. For addi‐
	      tional information, use the 'i' command.

       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      Enter the recovery & transformation  menu.  This	menu  includes
	      emergency	 recovery options (to fix damaged GPT data structures)
	      and options to transform to or from other partitioning  systems,
	      including creating hybrid MBRs.

       s      Sort partition entries. GPT partition numbers need not match the
	      order of partitions on the disk. If you want them to match,  you
	      can use this option.  Note that some partitioning utilities sort
	      partitions whenever they make  changes.  Such  changes  will  be
	      reflected	 in  your  device  filenames,  so you may need to edit
	      /etc/fstab if you use this option.

       t      Change a single partition's type code. You enter the  type  code
	      using  a	two-byte hexadecimal number, as described earlier. You
	      may also enter a GUID  directly,	if  you	 have  one  and	 gdisk
	      doesn't know it.

       v      Verify  disk. This option checks for a variety of problems, such
	      as incorrect CRCs and mismatched	main  and  backup  data.  This
	      option does not automatically correct most problems, though; for
	      that, you must use options  on  the  recovery  &	transformation
	      menu.  If no problems are found, this command displays a summary
	      of unallocated disk space.

       w      Write data. Use this command to save your changes.

       x      Enter the experts' menu. Using this option  provides  access  to
	      features you can use to get into even more trouble than the main
	      menu allows.

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

       The second gdisk menu is the recovery & transformation menu, which pro‐
       vides access to data recovery  options  and  features  related  to  the
       transformation  of  partitions between partitioning schemes (converting
       BSD disklabels  into  GPT  partitions  or  creating  hybrid  MBRs,  for
       instance).   A  few options on this menu duplicate functionality on the
       main menu, for the sake of convenience. The options on this menu are:

       b      Rebuild GPT header from backup.  You  can	 use  the  backup  GPT
	      header  to  rebuild  the	main GPT header with this option. It's
	      likely to be useful if your  main	 GPT  header  was  damaged  or
	      destroyed (say, by sloppy use of dd).

       c      Load  backup  partition  table.  Ordinarily, gdisk uses only the
	      main partition table (although the backup's integrity is checked
	      when  you	 launch	 the program). If the main partition table has
	      been damaged, you can use this option to load  the  backup  from
	      disk  and	 use  it instead. Note that this will almost certainly
	      produce no or strange partition entries if you've just converted
	      an  MBR disk to GPT format, since there will be no backup parti‐
	      tion table on disk.

       d      Use main GPT header and  rebuild	the  backup.  This  option  is
	      likely to be useful if the backup GPT header has been damaged or

       e      Load main partition table. This option reloads the  main	parti‐
	      tion  table  from	 disk. It's only likely to be useful if you've
	      tried to use the backup partition table (via 'c')	 but  it's  in
	      worse shape then the main partition table.

       f      Load  MBR	 and  build fresh GPT from it. Use this option if your
	      GPT is corrupt or conflicts with the MBR and you want to use the
	      MBR as the basis for a new set of GPT partitions.

       g      Convert GPT into MBR and exit. This option converts as many par‐
	      titions as possible into MBR form, destroys the GPT data	struc‐
	      tures,  saves the new MBR, and exits.  Use this option if you've
	      tried GPT and find that MBR works better	for  you.   Note  that
	      this  function  generates	 up  to four primary MBR partitions or
	      three primary partitions and as many logical partitions  as  can
	      be generated. Each logical partition requires at least one unal‐
	      located block immediately before its first block. Therefore,  it
	      may be possible to convert a maximum of four partitions on disks
	      with tightly-packed  partitions;	however,  if  free  space  was
	      inserted	between	 partitions when they were created, and if the
	      disk is under 2 TiB in size, it should be	 possible  to  convert
	      all the partitions to MBR form.  See also the 'h' option.

       h      Create  a	 hybrid	 MBR.  This is an ugly workaround that enables
	      GPT-unaware OSes, or those that can't boot from a GPT  disk,  to
	      access up to three of the partitions on the disk by creating MBR
	      entries for them. Note that these hybrid MBR entries can	easily
	      go   out	of  sync  with	the  GPT  entries,  particularly  when
	      hybrid-unaware GPT utilities are used to edit the	 disk.	 Thus,
	      you  may need to re-create the hybrid MBR if you use such tools.
	      Unlike the 'g' option, this option does not  support  converting
	      any partitions into MBR logical partitions.

       i      Show detailed partition information. This option is identical to
	      the 'i' option on the main menu.

       l      Load partition data from a  backup  file.	 This  option  is  the
	      reverse  of the 'b' option on the main menu. Note that restoring
	      partition data from anything but the original disk is not recom‐

       m      Return  to  the  main  menu.  This  option  enables you to enter
	      main-menu commands.

       o      Print protective MBR data. You can see a summary of the  protec‐
	      tive  MBR's  partitions with this option. This may enable you to
	      spot glaring problems or	help  identify	the  partitions	 in  a
	      hybrid MBR.

       p      Print  the  partition table. This option is identical to the 'p'
	      option in the main menu.

       q      Quit without saving changes. This option is identical to the 'q'
	      option in the main menu.

       t      Transform	 BSD partitions into GPT partitions. This option works
	      on BSD disklabels held within GPT (or converted MBR) partitions.
	      Converted	 partitions'  type  codes  are	likely	to need manual
	      adjustment. gdisk will attempt to convert BSD disklabels	stored
	      on the main disk when launched, but this conversion is likely to
	      produce first and/or last partitions that are unusable. The many
	      BSD variants means that the probability of gdisk being unable to
	      convert a BSD disklabel is high compared to  the	likelihood  of
	      problems with an MBR conversion.

       v      Verify  disk.  This option is identical to the 'v' option in the
	      main menu.

       w      Write table to disk and exit. This option is  identical  to  the
	      'w' option in the main menu.

       x      Enter  the  experts'  menu.  This option is identical to the 'x'
	      option in the main menu.

       ?      Print the menu. This option (or any unrecognized entry) displays
	      a summary of the menu options.

       The  third gdisk menu is the experts' menu. This menu provides advanced
       options that aren't  closely  related  to  recovery  or	transformation
       between partitioning systems. Its options are:

       a      Set  attributes. GPT provides a 64-bit attributes field that can
	      be used to set features for each partition. gdisk supports  four
	      attributes:  system  partition,  read-only,  hidden,  and do not
	      automount. You can  set  other  attributes,  but	their  numbers
	      aren't  translated  into anything useful. In practice, most OSes
	      seem to ignore these attributes.

       c      Change partition GUID. You can enter a custom unique GUID for  a
	      partition	 using this option. (Note this refers to the GUID that
	      uniquely identifies a partition, not to its type code, which you
	      can  change  with	 the  't' main-menu option.) Ordinarily, gdisk
	      assigns this number randomly; however, you might want to	adjust
	      the number manually if you've wound up with the same GUID on two
	      partitions because of buggy GUID assignments (hopefully  not  in
	      gdisk) or sheer incredible coincidence.

       d      Display  the  sector alignment value. See the description of the
	      'l' option for more details.

       e      Move backup GPT data structures to the end of the disk. Use this
	      command  if  you've added disks to a RAID array, thus creating a
	      virtual disk with space that follows the backup GPT data	struc‐
	      tures.  This command moves the backup GPT data structures to the
	      end of the disk, where they belong.

       f      Randomize the disk's GUID and all partitions' unique GUIDs  (but
	      not  their partition type code GUIDs). This function may be used
	      after cloning a disk with another utility in order to render all
	      GUIDs once again unique.

       g      Change  disk GUID. Each disk has a unique GUID code, which gdisk
	      assigns randomly upon creation of the GPT data  structures.  You
	      can generate a fresh random GUID or enter one manually with this

       h      Recompute CHS values in protective or hybrid  MBR.  This	option
	      can  sometimes  help if a disk utility, OS, or BIOS doesn't like
	      the CHS values used by  the  partitions  in  the	protective  or
	      hybrid  MBR. In particular, the GPT specification requires a CHS
	      value of 0xFFFFFF for over-8GiB partitions, but  this  value  is
	      technically  illegal by the usual standards. Some BIOSes hang if
	      they encounter this value. This option  will  recompute  a  more
	      normal  CHS value -- 0xFEFFFF for over-8GiB partitions, enabling
	      these BIOSes to boot.

       i      Show detailed partition information. This option is identical to
	      the 'i' option on the main menu.

       l      Change  the sector alignment value. Disks with more logical sec‐
	      tors per	physical  sectors  (such  as  modern  Advanced	Format
	      drives),	some  RAID  configurations,  and many SSD devices, can
	      suffer performance problems if partitions are not aligned	 prop‐
	      erly for their internal data structures. On new disks, GPT fdisk
	      attempts to align partitions on 2048-sector (1MiB) boundaries by
	      default,	which  optimizes  performance  for  all	 of these disk
	      types. On pre-partitioned disks, GPT fdisk attempts to  identify
	      the  alignment  value  used  on that disk, but will set 8-sector
	      alignment on disks larger than 300 GB even if  lesser  alignment
	      values  are detected. In either case, it can be changed by using
	      this option.

       m      Return to the main  menu.	 This  option  enables	you  to	 enter
	      main-menu commands.

       n      Create a new protective MBR. Use this option if the current pro‐
	      tective MBR is damaged in a way that gdisk doesn't automatically
	      detect  and correct, or if you want to convert a hybrid MBR into
	      a "pure" GPT with a conventional protective MBR.

       o      Print protective MBR data. You can see a summary of the  protec‐
	      tive  MBR's  partitions with this option. This may enable you to
	      spot glaring problems or	help  identify	the  partitions	 in  a
	      hybrid MBR.

       p      Print  the  partition table. This option is identical to the 'p'
	      option in the main menu.

       q      Quit without saving changes. This option is identical to the 'q'
	      option in the main menu.

       r      Enter  the recovery & transformations menu. This option is iden‐
	      tical to the 'r' option on the main menu.

       s      Resize partition table. The default partition table size is  128
	      entries.	 Officially,  sizes  of	 less  than 16KB (128 entries,
	      given the normal entry size) are unsupported by the GPT specifi‐
	      cation;  however,	 in  practice they seem to work, and can some‐
	      times be useful in converting MBR disks. Larger sizes also  work
	      fine.  OSes  may impose their own limits on the number of parti‐
	      tions, though.

       t      Swap two partitions' entries in the partition table. One	parti‐
	      tion  may be empty. For instance, if partitions 1-4 are defined,
	      transposing 1 and 5 results in a table with partitions  numbered
	      from  2-5.  Transposing  partitions in this way has no effect on
	      their disk space allocation; it only alters their order  in  the
	      partition table.

       u      Replicate	 the  current  device's	 partition  table  on  another
	      device. You will be prompted to type the new device's  filename.
	      After  the  write	 operation completes, you can continue editing
	      the original device's partition table.  Note that the replicated
	      partition	 table	is  an exact copy, including all GUIDs; if the
	      device should have its own unique GUIDs, you should  use	the  f
	      option on the new disk.

       v      Verify  disk.  This option is identical to the 'v' option in the
	      main menu.

       z      Zap (destroy) the GPT data structures and exit. Use this	option
	      if  you want to repartition a GPT disk using fdisk or some other
	      GPT-unaware program.  You'll be given the choice	of  preserving
	      the  existing  MBR,  in  case it's a hybrid MBR with salvageable
	      partitions or if you've already created new MBR  partitions  and
	      want  to	erase  the  remnants of your GPT partitions. If you've
	      already created new MBR partitions, it's conceivable  that  this
	      option will damage the first and/or last MBR partitions! Such an
	      event is unlikely, but could occur if your  new  MBR  partitions
	      overlap the old GPT data structures.

       ?      Print the menu. This option (or any unrecognized entry) displays
	      a summary of the menu options.

       In many cases, you can press the Enter key to select a  default	option
       when  entering  data.  When  only one option is possible, gdisk usually
       bypasses the prompt entirely.

       As of March 2014 (version 0.8.10),  gdisk  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  by  the  author,
	      although	I've  heard of 64-bit versions being successfully com‐

       *      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

       *      The  fields used to display the start and end sector numbers for
	      partitions in the 'p'  command  are  14  characters  wide.  This
	      translates to a limitation of about 45 PiB. On larger disks, the
	      displayed columns will go out of alignment.

       *      In the Windows version, only ASCII characters are	 supported  in
	      the   partition  name  field.  If	 an  existing  partition  uses
	      non-ASCII UTF-16 characters, they're likely to be	 corrupted  in
	      the  'i' and 'p' menu options' displays; however, they should be
	      preserved when  loading  and  saving  partitions.	 Binaries  for
	      Linux, FreeBSD, and OS X support full UTF-16 partition names.

       *      The program can load only up to 128 partitions (4 primary parti‐
	      tions and 124 logical partitions) when converting from MBR  for‐
	      mat.   This   limit  can	be  raised  by	changing  the  #define
	      MAX_MBR_PARTS line in the basicmbr.h source code file and recom‐
	      piling;	however,   such	  a   change   will  require  using  a
	      larger-than-normal partition table. (The limit of 128 partitions
	      was  chosen  because  that number equals the 128 partitions sup‐
	      ported by the most common partition table size.)

       *      Converting from MBR format sometimes fails because  of  insuffi‐
	      cient space at the start or (more commonly) the end of the disk.
	      Resizing the partition  table  (using  the  's'  option  in  the
	      experts'	menu) can sometimes overcome this problem; however, in
	      extreme cases it may be necessary to resize  a  partition	 using
	      GNU Parted or a similar tool prior to conversion with gdisk.

       *      MBR  conversions work 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.

       *      BSD disklabel support can create first  and/or  last  partitions
	      that overlap with the GPT data structures. This can sometimes be
	      compensated by  adjusting	 the  partition	 table	size,  but  in
	      extreme cases the affected partition(s) may need to be deleted.

       *      Because  of  the	highly variable nature of BSD disklabel struc‐
	      tures, conversions from this form may be	unreliable  --	parti‐
	      tions  may  be dropped, converted in a way that creates overlaps
	      with other partitions, or converted with incorrect start or  end
	      values. Use this feature with caution!

       *      Booting  after converting an MBR or BSD disklabel disk is likely
	      to be disrupted. Sometimes re-installing a boot loader will  fix
	      the  problem,  but other times you may need to switch boot load‐
	      ers. Except on EFI-based platforms,  Windows  through  at	 least
	      Windows  7  doesn't  support  booting from GPT disks. Creating a
	      hybrid MBR (using the 'h' option on the recovery	&  transforma‐
	      tion  menu)  or  abandoning GPT in favor of MBR may be your only
	      options in this case.

       Primary author: Roderick W. Smith (


       * Yves Blusseau (

       * David Hubbard (

       * Justin Maggard (

       * Dwight Schauer (

       * Florian Zumbiehl (

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

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

Roderick W. Smith		    0.8.10			      GDISK(8)

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