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Using GPT or MBR for a pure backup drive.


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#1 Nozyspy

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Posted 10 February 2016 - 01:12 PM

I'm not sure if this is the right place to put this, but this forum is the closest I could find to what my question is.
 
I have got a second internal harddrive to use as a pure backup drive for stuff like pictures, vids, music etc. (no system stuff) and when it asks me to initialize the drive it asks for either MBR or GPT.
 
To the best of what I have been able too find out so far, the main advantages of GPT are to do with partition size, and drives over 2TB. However since the drive is only 1TB that doesn't seem useful.
 
However it seems that MBR is more susceptible to boot corruption because the partition and boot data is only stored in one place, whereas GPT has redundant copies. The main issue with GPT seems to be compatibility.
 
I am really baffled, on the one hand I have seen lots of people say just to use MBT because it is tried and tested and GPT is only useful for drives over 2TB. But then on the other hand since this is a backup drive and I want that data to be safe, does GPT provide any advantage in terms of the redundant partition data, even though it will never be used as a boot drive?
 
Also I presume that the (non system) files and folders that will go in the backup would be able to be restored from a MBR drive to GPT drive (if upgrading to a new version of Windows in the future) and vice versa? I read that an MBR backup couldnt be restored to a GPT drive, but I am assuming that is an entire system image with the operating system and not just select files and folders?
 
So far I would say that from what I have read there seems to be more of a leaning towards people just using MBR.
 
Any advice would be much appreciated!


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#2 JohnC_21

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Posted 10 February 2016 - 01:33 PM

If the computer has BIOS and not the new UEFI then I would go with MBR as GPT disks on computers with the old BIOs can have compatibility issues. Edit: These compatibility issues are mostly related to GPT boot disks but I would still use MBR if you have the old BIOS firmware.

 

GPT does offer better protection from corruption of the partition table as it keeps a backup. 

 

http://en.community.dell.com/techcenter/extras/w/wiki/2838

 

Edit: In regards to the other question, you can transfer backed up files from MBR backup to a GPT disk with not problem. If you used Macrium Reflect Free to create a MBR disk image, you could still use it's feature of mounting the image as a virtual disk to pull files from the disk image and copy them to a GPT disk. But you are right, you cannot do a disk image of an MBR disk and restore it to a GPT disk. Data disks without an OS can be converted between MBR and GPT using a third party partition manager.

 

 

GPT data structures are also well defined and stored twice on the disk: once at the start and again at the end. This improves the odds of successful data recovery resulting from damage caused by an accident or a bad sector. Also, cyclic redundancy check (CRC) values are computed for critical data structures, improving the odds of detecting of data corruption. The figure below shows the layout of a GPT disk and how the data structure is stored.

gmvpr7wbglebupttthnjka74704.jpeg


Edited by JohnC_21, 10 February 2016 - 01:49 PM.


#3 Nozyspy

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Posted 10 February 2016 - 02:19 PM

 

If the computer has BIOS and not the new UEFI then I would go with MBR as GPT disks on computers with the old BIOs can have compatibility issues. Edit: These compatibility issues are mostly related to GPT boot disks but I would still use MBR if you have the old BIOS firmware.

 

GPT does offer better protection from corruption of the partition table as it keeps a backup. 

 

http://en.community.dell.com/techcenter/extras/w/wiki/2838

 

Edit: In regards to the other question, you can transfer backed up files from MBR backup to a GPT disk with not problem. If you used Macrium Reflect Free to create a MBR disk image, you could still use it's feature of mounting the image as a virtual disk to pull files from the disk image and copy them to a GPT disk. But you are right, you cannot do a disk image of an MBR disk and restore it to a GPT disk. Data disks without an OS can be converted between MBR and GPT using a third party partition manager.

 

 

 

 

Its a very new machine, so it has UEFI. As to your second point, this means that I could not restore ANY files from my backup disk if I initialized it as GPT, because my main disk with Win 7 is MBR? That would seem to defeat the point of a backup disk. :S

 

It isnt a system image, just certain folders and files, like pictures and such.



#4 JohnC_21

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Posted 10 February 2016 - 02:34 PM

I meant you cannot restore a full disk image of an MBR OS disk to a GPT disk. You can restore files from the backup of an MBR disk to a GPT disk without a problem. 



#5 Nozyspy

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Posted 10 February 2016 - 02:54 PM

I meant you cannot restore a full disk image of an MBR OS disk to a GPT disk. You can restore files from the backup of an MBR disk to a GPT disk without a problem. 

 

Hmm ok, but if I backup some files from my MBR OS disk to a backup disk that is GPT, can I still restore those files back from the GPT backup disk to the MBR OS disk?

 

 

 

Sorry all if this is rather confusing to me, I didnt realise the were any of these differences till the other day! I may be over thinking things here, I just wanted my backup disk to be a safe as possible, but I dont want to over complicate thingns!



#6 JohnC_21

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Posted 10 February 2016 - 03:32 PM

I don't know how you backup program works but if you copying files from an MBR disk to a GPT disk and back is no problem. If your backup program simply extracts the files and then copies them from the MBR backup image to the GPT disk I see no problem. If concerned, try an experiment. Format the data disk as GPT and recover some files from the MBR disk backup image. You should not have any problem.

 

If you have a UEFI computer then format the disk as GPT. You can do it easily using Partition Wizard. First you need to initialize the disk as GPT. This can only be done with no partitions on the disk. Then create a partition and format is NTFS.

 

MBR and GPT disks are basically different in the way they boot and the partition table setup. Backing up and restoring files to a pure DATA whether a MBR or GPT disk should not matter. You do it all the time when copying files from a MBR USB flash drive to a GPT disk. 



#7 Nozyspy

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Posted 10 February 2016 - 05:20 PM

Hmmmmm. Well I am just using windows backup feature to backup certain folders. I thought GPT and UEFI was only an issue if the disk was going to be the OS disk? Right now my OS disk is just MBR from the Windows 7 install and there doesn't seem to be any issues with the UEFI system on the mobo.

 

Right now I am thinking its just going to be easier and less hassle to go with MBR, so as to avoid any issues. Are the redundant partition data files worth all the extra messing around and worry that there may be issues with the drive afterwards?



#8 JohnC_21

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Posted 10 February 2016 - 06:34 PM

If your computer is UEFI then the disk has be GPT in order for it to boot. You cannot boot an MBR disk on a UEFI computer.It is possible to install Windows on a MBR disk if you change UEFI mode to Legacy or CSM mode in the UEFI settings. From your post, I am assuming you are saying you installed Windows 7 on a UEFI computer.

 

Open a command prompt and type the following

 

diskpart

list disk

 

Is there an "*" asterisk under GPT for your boot disk which should be disk 0.

 

http://www.howtogeek.com/193669/whats-the-difference-between-gpt-and-mbr-when-partitioning-a-drive/

 

Windows can only boot from GPT on UEFI-based computers running 64-bit versions of Windows 10, 8.1, 8, 7, Vista, and corresponding server versions. All versions of Windows 10, 8.1, 8, 7, and Vista can read GPT drives and use them for data — they just can’t boot from them without UEFI.


Edited by JohnC_21, 10 February 2016 - 06:34 PM.


#9 Nozyspy

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Posted 10 February 2016 - 06:49 PM

 

If your computer is UEFI then the disk has be GPT in order for it to boot. You cannot boot an MBR disk on a UEFI computer.It is possible to install Windows on a MBR disk if you change UEFI mode to Legacy or CSM mode in the UEFI settings. From your post, I am assuming you are saying you installed Windows 7 on a UEFI computer.

 

Open a command prompt and type the following

 

diskpart

list disk

 

Is there an "*" asterisk under GPT for your boot disk which should be disk 0.

 

http://www.howtogeek.com/193669/whats-the-difference-between-gpt-and-mbr-when-partitioning-a-drive/

 

Windows can only boot from GPT on UEFI-based computers running 64-bit versions of Windows 10, 8.1, 8, 7, Vista, and corresponding server versions. All versions of Windows 10, 8.1, 8, 7, and Vista can read GPT drives and use them for data — they just can’t boot from them without UEFI.

 

 

Nope there are no asterisks under GPT, it is definitely a MBR drive.

 

From the quote you posted at the bottom, I would presume that means that you can only boot from a GPT drive if you are using a UEFI based system, as opposed to the drive having to be GPT to boot from it. I definitely haven't had any issues.



#10 JohnC_21

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Posted 10 February 2016 - 07:12 PM

Yes, if the computer is set to UEFI mode then the HDD must be GPT unless the mode was set to Legacy or CSM boot in UEFI settings.

 

If you enter your UEFI/BIOS is should say if it is UEFI and if the mode is Legacy or CSM.

 

Here is another page on UEFI/MBR

 

  1. A UEFI system can boot only from a GPT disk, not MBR. (A BIOS system can boot only from an MBR disk and not GPT, which is why you can't take an OS disk from a BIOS system and put it in a UEFI system and expect the system to boot.)

     

     



#11 Nozyspy

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Posted 25 February 2016 - 05:06 AM

Hmmm well looking at the settings it does appear to be in some kind of compatibility mode, since the boot drive is definitely MBR.

 

Back to the original question though, I think MBR should be fine for initializing a pure backup drive right? I would rather avoid any conflicts or anything I am not familiar with.



#12 JohnC_21

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Posted 25 February 2016 - 10:23 AM

I don't see any problem using a GPT initialized disk for backups. The only problem would be if you had an external GPT data disk and tried to explore the contents on XP. XP 32bit would not detect the disk.






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