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  • GParted & protective MBR.

    From peter@3:633/10 to All on Tuesday, May 26, 2026 21:30:01
    Hi,

    When GParted creates a GUID partition table, is a protective MBR
    created automatically? Is any interaction from me necessary or
    advisable?

    Answers may be in documentation but I haven't found them. A link is
    welcome.

    Thanks, ... P.

    --
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    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Charles Curley@3:633/10 to All on Tuesday, May 26, 2026 23:20:02
    On 26 May 2026 12:02:51 -0700
    peter@easthope.ca wrote:

    When GParted creates a GUID partition table, is a protective MBR
    created automatically? Is any interaction from me necessary or
    advisable?

    I haven't the foggiest idea. I suggest you do the experiment, then
    check your results with gdisk.

    --
    Does anybody read signatures any more?

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    https://charlescurley.com/blog/

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From David Wright@3:633/10 to All on Wednesday, May 27, 2026 06:50:02
    On Tue 26 May 2026 at 12:02:51 (-0700), peter@easthope.ca wrote:
    When GParted creates a GUID partition table, is a protective MBR
    created automatically?

    I would very much expect it to, but I too would advise checking it
    after you have finished using gparted.

    Is any interaction from me necessary or advisable?

    I would also expect you to create some partitions as well. At this
    point, things aren't so clear. I've read that gparted my change the
    protective MBR to a hybrid? one under some circumstances. However,
    I don't know what those circumstances are.

    Answers may be in documentation but I haven't found them.

    Neither can I find matches for "protective" or "hybrid" in the manual.ý

    A link is welcome.

    I would recommend using gdisk. There's a cgdisk variant that uses
    curses if you need a display, rather than typing p occasionally.
    You could hardly do better than start reading at: https://www.rodsbooks.com/gdisk/
    which has more resources at the end of that page. (Some of the links
    duplicate the documentation contained in the gdisk package itself.)


    ?
    https://www.rodsbooks.com/gdisk/hybrid.html
    ý
    https://gparted.org/display-doc.php?name=help-manual

    Cheers,
    David.

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Marco Moock@3:633/10 to All on Wednesday, May 27, 2026 10:50:02
    Am 26.05.26 um 21:30 schrieb peter@easthope.ca:
    When GParted creates a GUID partition table, is a protective MBR
    created automatically? Is any interaction from me necessary or
    advisable?

    I recommend having a protected MBR, legacy (MBR only software) will
    detect that an MBR will a partition exist.

    Just give it a try and check the output of gdisk - it will show you if
    the protective MBR is present.

    --
    Gruá
    Marco

    Spam bitte an abfalleimer2001@stinkedores.dorfdsl.de

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From didier gaumet@3:633/10 to All on Wednesday, May 27, 2026 11:20:02
    Le 26/05/2026 … 21:02, peter@easthope.ca a ‚crit˙:
    Hi,

    When GParted creates a GUID partition table, is a protective MBR
    created automatically? Is any interaction from me necessary or
    advisable?

    Answers may be in documentation but I haven't found them. A link is
    welcome.

    Thanks, ... P.

    Hello,

    (I am not knowledgeable on this subject)

    GPT specs on uefi.org seem to mandate the use of protective MBR (MBR
    partition table: legacy MBR, GPT partition table: protective MBR): https://uefi.org/specs/UEFI/2.10/05_GUID_Partition_Table_Format.html?__cf_chl_tk=SMjqN9spMdn1nhVis_qsEGSMd38ei83cxqk77OzivLE-1779826234-1.0.1.1-zcn5OFq5VKgR9Pecqr_vCgmepxsdiUu6PMutn0FGStE#lba-0-format

    Hybrid MBR seems to be a sort of trick to use with enhanced BIOSes that
    manage GPT but are not UEFI compliant

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Marco Moock@3:633/10 to All on Wednesday, May 27, 2026 11:50:01
    Am 27.05.26 um 11:20 schrieb didier gaumet:
    Hybrid MBR seems to be a sort of trick to use with enhanced BIOSes that manage GPT but are not UEFI compliant

    No, Hybrid MBR is situations with machines that can only read MBR, and machines that can only read GPT. It is dangerous, as any modification of
    the partition table needs to be done in both tables.
    I recommend avoiding that.

    Every old BIOS can boot from the GPT disk, as it only reads the boot sector. Although, certain boot managers are too fat for the 1st sector and need
    a special (really small) bios_gpt partition on GPT disks.

    --
    Gruá
    Marco

    Spam bitte an abfalleimer2001@stinkedores.dorfdsl.de

    --- PyGate Linux v1.5.15
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)