Convert Hybrid GPT/MBR to pure GPT partition scheme
From the gdisk(8)
manual:
n
– Create a new protective MBR. Use this option if the current protective 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.
You need to enter the experts’ menu to access this option.
-
Open the drive in
gdisk
:sudo gdisk /dev/sdX
Enter the experts’ menu (
x
).Create a new protective MBR (
n
) and answer any dialogue questions as suitable.Return to the main menu (
m
).Write the changes to the drive and exit gdisk (
w
).
You may need to reinstall Grub in EFI mode if it was installed in MBR mode before.
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coolcatco888
Updated on September 18, 2022Comments
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coolcatco888 over 1 year
I was wondering how to safely convert a Hybrid GPT/MBR to a pure GPT partition scheme? (Without Reformatting)
The reason why I ask is, I currently triple-boot with Ubuntu 16.04 LTS, Windows 10 and Mac OSX Lion.
Originally I needed to format my drive with a Hybrid partition scheme to install Windows 7 but I have since upgraded to Windows 10.
I know now that Windows 10 supports booting from GPT partitions and I would like to covert everything to a pure GPT partition scheme without reformatting.
If I can do this, I would be able to reformat my HFS+ partition to an APFS partition and install High Sierra.
So the questions are:
- How do I convert my Hybrid MBR to a pure GPT?
- Will it break booting into any of my OSes if I do? (Windows 10, Linux, MacOSX)
Here is my gdisk output:
GPT fdisk (gdisk) version 1.0.1 Partition table scan: MBR: hybrid BSD: not present APM: not present GPT: present Found valid GPT with hybrid MBR; using GPT. Command (? for help): p Disk /dev/sda: 3907029168 sectors, 1.8 TiB Logical sector size: 512 bytes Disk identifier (GUID): CBC86EEB-C878-4C46-9963-120433EB0BED Partition table holds up to 128 entries First usable sector is 34, last usable sector is 3907029134 Partitions will be aligned on 8-sector boundaries Total free space is 269477 sectors (131.6 MiB) Number Start (sector) End (sector) Size Code Name 1 40 409639 200.0 MiB EF02 EFI System Partition 2 409640 293378391 139.7 GiB AF00 Mac OSX 3 293642240 684265471 186.3 GiB 0700 WINDOWS 7 4 684265472 1075085311 186.4 GiB 0700 LINUX 5 1075085865 1087375589 5.9 GiB 8200 6 1087375590 3907024064 1.3 TiB 0700
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phuclv almost 6 yearseven Windows 7 supports booting from UEFI natively
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oldfred almost 6 yearsReview issues: rodsbooks.com/gdisk/hybrid.html Biggest issue is whether you can even convert a Windows BIOS boot to UEFI without re-installing, but this is an Ubuntu site and we do not know that. Converting from MBR to gpt: ubuntuforums.org/showthread.php?t=1454252
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G5tube about 4 yearsIt works as described. In fact I was able to restore broken APFS Volume on a hybrid partition. You need to have knowledge of the layout of the partitioning. For more info see this post: apple.stackexchange.com/questions/390955/…
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coolcatco888 almost 6 yearsI'm using OSX Lion right now but as of this afternoon, I installed clover as my bootloader and now I cannot boot into it.
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coolcatco888 almost 6 yearsActually, could you know if it is safe to reformat just the MacOSX partition? If so, would I also be able to reformat it as a APFS partition?
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aarnphm almost 6 years@coolcatco888 I think that the only solution for your problem is that you can either stick with what you have right now or do a backup for your files in all OSes then do a fresh reinstall and format the drive as GPT. And I don't think you should reformat the OS partition because you can accidentally delete your bootloader.
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coolcatco888 almost 6 yearsI think I will continue using it as a Hybrid MBR/GPT setup since there are no clear answers on whether it will work and what sort of pitfalls there are. My intent is simply to reformat the HFS+ partition and do a clean install of High Sierra. Lastly, Is it safe to simply reformat the HFS+ partition only without breaking anything? (Correct me if I am wrong, I think I may have to resync my Hybrid MBR with gdisk after installing High Sierra)
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David Foerster almost 6 years@coolcatco888: You can save the entire current partition table with gdisk (
b
in the main menu), make the above (or any) changes, see what happens and restore the partition table to its previous state with gdisk again (l
in the recovery & transformation sub-menu). -
tmm1 over 3 yearsThanks! Is there any way to do the same with sgdisk?
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David Foerster over 3 years@tmm1: This question is specifically about
gdisk
. However, yours sounds like an excellent new question. I also found a similar one with the right answer. -
coolcatco888 about 3 yearsI actually realized that reformatting or changing any partitions on a hybrid gpt will revert it back to a protective MBR. I can use the gdisk method to do this as well. In my case, I still needed the Hybrid MBR.