On Wed, 9 Oct 2013, Karel Zak <kzak@xxxxxxxxxx> wrote: [...]
It's more generic problem, we ignore MBR for hybrid GPT on more places (for example in kernel and libblkid).
That's fine and fair enough, but fdisk *really* does need to be able to bypass GPT when necessary.
(Just for the record, hybrid GPT is ugly non-standard hack.)
Oh, I'm perfectly aware of that. :D I'm using it to force Win7 to dual-boot via BIOS (as opposed to UEFI) whilst having GPT partitioning for Linux and OSX. Basically, GPT set up as it should be, and a hybrid MBR set up specifically to trick Micro$oft's garbage into booting, since it refuses to boot from GPT with UEFI disabled.
[...]
# fdisk -l /dev/sda
Disk /dev/sda: 149.1 GiB, 160041885696 bytes, 312581808 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: gpt Disk identifier: 3549290F-417C-4941-8503-F7835109B821
Device Start End Size Type /dev/sda1 2048 2050047 1000M EFI System /dev/sda2 2050048 6146047 2G Microsoft basic data /dev/sda3 6146048 26462207 9.7G Linux swap /dev/sda4 26462208 98142207 34.2G Microsoft basic data /dev/sda5 98142208 230662143 63.2G Microsoft basic data /dev/sda6 230662144 312580095 39.1G Microsoft basic data
but when GPT is disabled we can access PMBR:
# fdisk -l -t dos /dev/sda
Disk /dev/sda: 149.1 GiB, 160041885696 bytes, 312581808 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x00000000
Device Boot Start End Blocks Id System /dev/sda1 1 312581807 156290903+ ee GPT
Yes; _exactly_ what is needed, plus IMO a switch from within fdisk's menu system (Expert?) that would allow switching between GPT and MBR (or anything else that might be present).
Cheerio, Craig -- To unsubscribe from this list: send the line "unsubscribe util-linux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
