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65 votes
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Converting between GPT and MBR hard drive without losing data

You can convert from GPT to MBR and MBR to GPT without data loss (I have tried that) with gdisk in Linux. Use at your own risk Run command gdisk /dev/sdx with sdx as per your HDD partition GPT ...
Krunal Mevada's user avatar
48 votes

Mac OS X This Disk doesn't use the GUID partition Scheme when upgrading to Mac OS Sierra

In Disk Utility, near the close/minimize/fullscreen buttons, you can see a "View" mode dropdown menu. Set the view mode to "Show All Devices", then you'll see the "root" drives. Click on a root drive, ...
PragmaticEngineer's user avatar
40 votes

How to add Windows 10 to grub boot loader?

Boot to your Linux Open a Terminal window Type: sudo os-prober If the results identify a Windows 10 install, type sudo update-grub which will update the GRUB entries and add it Reboot your computer ...
Kinnectus's user avatar
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37 votes
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Are GPT partitions less likely to get corrupted than MBR-based partitions?

According to Wikipedia, there is redundancy in the GPT scheme. The GPT table is written at the beginning of the disk, as well as at the end of the disk (see image). In addition each GPT table has a ...
mtak's user avatar
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32 votes
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Why doesn't installing GRUB on MBR destroy the partition table?

The software reads the original sector; updates it in memory; then writes out the updated sector. On Linux, this is actually done by the OS itself, so GRUB doesn't need to worry about sectors – it can ...
u1686_grawity's user avatar
21 votes

How to fix the Windows 10 boot loader from Windows

The other answers given here work great on MBR/BIOS systems, however if you're on a UEFI system like I am, bootsect will just write a semi-functional boot MBR over the GPT protective MBR and bootrec ...
Nathan2055's user avatar
  • 1,220
16 votes
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MBR or GPT for external backup drive

GPT is much more resilient against data corruption because of the CRC and because it stores multiple copies of the partitioning and boot data, so recovery is still possible after a catastrophic data ...
harrymc's user avatar
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16 votes
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What are all those partition table type in gparted?

What are those available partition table types in gparted useful for? The options you mention (other than Atari) are covered below (and I guess Atari is there to support Atari partition tables). ...
DavidPostill's user avatar
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14 votes

Cloned disk - duplicate disk signature, how to resolve?

You should be able to fix colliding disk signatures with the diskpart command line utility that comes with Windows. It allows you to view and change the disk signature. Open a command prompt (cmd....
wp78de's user avatar
  • 1,712
13 votes

How can I solve this MBR2GPT issue?

To clarify @merle 's VERY helpful answer - I had to run the command below to copy my working EFI boot data to a place where mbr2gpt could find it. bcdboot c:\Windows /f bios /s c: Once you've done ...
Vince Anido's user avatar
13 votes
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If my motherboard does not support UEFI BIOS, can I still use GPT for non boot drives?

Non-boot GPT disks are supported on BIOS-only systems It is not necessary to boot from UEFI in order to utilize disks partitioned with the GPT partition scheme. Therefore you can take advantage of all ...
I say Reinstate Monica's user avatar
12 votes
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Clonezilla fails at cloning with mismatched GPT and MBR partition

Important - Kindly Note Kindly request you to go through @Tetsujin's comment below. When he tried the same answer, there was data loss. So, I assume this answer is no longer fully correct. Hence ...
Rahul's user avatar
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11 votes
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What is a "UEFI-bootable" USB flash drive and can I boot it on legacy BIOS?

Most UEFI implementations can also boot from MBR-partitioned USB drives. They expect a file at /efi/boot/bootx64.efi to exist. For best compatibility, using the FAT32 filesystem is highly recommended. ...
Daniel B's user avatar
  • 63.3k
11 votes

Converting between GPT and MBR hard drive without losing data

Making your drive bootable This is an enhancement to the information provided by Krunal and clarkttfu with more details on the steps to create a BIOS boot partition and install grub to it. If you ...
johnf's user avatar
  • 231
10 votes
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In Linux, how do you delete the partition table from a disk?

You can just write some zeros to the first sector of the disk in question, for example you want to erase partition table of sda: dd if=/dev/zero of=/dev/sda bs=512 count=1 That would fill first ...
SparedWhisle's user avatar
  • 4,185
10 votes
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How can I migrate a Windows 10 from BIOS/MBR boot to UEFI/GPT without reinstalling?

Starting with Windows 10 Version 1703 (Creators Update, Build 15063), there is a tool called MBR2GPT.EXE included which does all steps. Best is to boot from a Win10 v1703 DVD/USB drive to the repair ...
magicandre1981's user avatar
10 votes

If my motherboard does not support UEFI BIOS, can I still use GPT for non boot drives?

Although Twisty’s answer somewhat hints at it, I’ll spell it out: BIOS does it all. In fact, GPT or MBR don’t matter at all. The BIOS will simply load the first sector of the HDD/SDD into RAM and ...
Daniel B's user avatar
  • 63.3k
10 votes

Making sense of the 2TB MBR partition limit

Is the 2TiB limit a partition limitation, or a total disk/volume limitation? If it's the former, is it possible to increase the usable space of a disk by creating further partitions less than 2TiB on ...
Bob's user avatar
  • 61.7k
8 votes

How to partition MBR external hdd on Mac?

You can use Terminal diskutil partitionDisk /dev/disk7 MBR fat32 "NO NAME" 100% Replace number 7 on "disk7" with actual disk number.. GPT: GUID Partition Table APM: Apple Partition Map MBR: Master ...
D.A.H's user avatar
  • 181
8 votes
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Can I chainload MBR from Grub on secondary GPT drive? And can I nuke MSR on secondary drive?

My problems stemmed from confusion and lack of knowledge. I will try to summarise what I've learned here in the hope that some one finds it useful. BIOS vs UEFI Hardware When your power on your ...
Emily L.'s user avatar
  • 534
8 votes

Cloned disk - duplicate disk signature, how to resolve?

As @Interminable said in the comment to the other answer, the solution for me was to just right-click on the offline disk and select 'Online'.
Jonas Sourlier's user avatar
8 votes
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How to fix a partition detected as RAW, when Chkdsk correctly reads it as NTFS?

In the end, after I used TestDisk to copy all the important files off the disk, I finally risked running chkdsk /f and it didn't detect any problems, but apparently removed the "requires checking" ...
Sinus the Tentacular's user avatar
8 votes
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Cannot convert from MBR to GPT

Hidden just means that the OS won't mount those partitions automatically. It isn't related to the success or failure of the conversion, since it's just a different value in the partition type field, ...
phuclv's user avatar
  • 27.9k
8 votes

Is is safe to copy a partition bitwise between MBR and GPT partition tables?

There’s none. Neither MBR nor GPT deal with what’s inside partitions. You can clone a partition from MBR to GPT and vice versa and still access all the data normally. While staying within limits (like ...
Daniel B's user avatar
  • 63.3k
7 votes
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How can a MBR formatted hard drive exceed 1.81 TiB capacity?

Your USB drive presents itself to the host computer with a logical sector size of 4096 bytes, and that's what enables it to be partitioned with an MBR partition table that can use more than 2 TB of ...
balazer's user avatar
  • 301
7 votes
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Why does a GPT formatted disk have the MBR? Protective MBR

Legacy tools will simply 'see' a partition in legacy partition table (MBR) occupying the entire disk and as such the partition (hopefully) 'protects' the drive from new and overlapping partitions ...
Joep van Steen's user avatar
6 votes

How can I solve this MBR2GPT issue?

I have tried all of the mentioned solutions, but none of them worked for me. However, I found out what was the main reason for the problem and solved it. When I ran diskpart and saw the details of ...
Zabota's user avatar
  • 61
6 votes
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HDD appears to have both MBR and GPT

gdisk (“GPT fdisk”) has a one-step(-ish) option to create a protective MBR. $ gdisk /dev/sdb x n w This will: Launch gdisk Enter expert mode “create a new protective MBR” “write table to disk and ...
Daniel B's user avatar
  • 63.3k
6 votes
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What is the maximum size of hard-drive used MBR partitioning?

However, it seems that the Partition size is limited by the 32bit size of capacity field in the partition table. This is (2^32)-1 x 512 byte = 2TB. Basically yes, if the sector size is 512 bytes. ...
Kamil Maciorowski's user avatar
6 votes
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What is the best way to move MBR and bootmgr to new drive (Windows 10)?

The 'bcdboot' tool is enough. (It is even possible to install Windows with only 'dism' and 'bcdboot'.) For BIOS mode: Create or choose the 'system' partition – an NTFS partition that'll hold the ...
u1686_grawity's user avatar

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