Author Topic: Airboot & GPT  (Read 6559 times)

Per E. Johannessen

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Airboot & GPT
« on: January 24, 2020, 08:53:29 pm »
On a system I have two hdd's, one MBR with ArcaOS and one GPT with Win10. Airboot skips GPT disks so it can't boot Win10.
AFAIK the GPT disk has to be converted to MBR for Airboot to see it. Has anyone tried EaseUS Partition Master which claim to keep all data/partitioning on the GPT disk intact, or does anyone have another solution?

Martin Iturbide

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Re: Airboot & GPT
« Reply #1 on: January 24, 2020, 09:00:06 pm »
Hi Per.

I don't have much experience on this area, I did it once to convert a GPT HDD to MBR.
I used as reference this two articles and I wrote the links on the wiki. Maybe someone with more experience can help on this topic.

Lately what I had done is to wipe all the HDD, re-create the partitions with ArcaOS and reinstall Windows 10 from scratch, but I understand that it may not be what you are looking for.

(Always remember to backup your files when you are trying this kind of stuff)

Regards
Martin Iturbide
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roberto

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Re: Airboot & GPT
« Reply #2 on: January 24, 2020, 10:04:38 pm »
Has anyone tried EaseUS Partition Master which claim to keep all data/partitioning on the GPT disk intact, or does anyone have another solution?
I don't remember what version I had of Easeus, but when trying to restore a backup of a GPT disk with win10, I couldn't restore it to an MBR disk.Finally I had to delete it, convert it and reinstall.
Does anyone know how the development of the GPT is?

saludos

Remy

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Re: Airboot & GPT
« Reply #3 on: January 25, 2020, 01:24:04 am »
Has anyone tried EaseUS Partition Master which claim to keep all data/partitioning on the GPT disk intact, or does anyone have another solution?
I don't remember what version I had of Easeus, but when trying to restore a backup of a GPT disk with win10, I couldn't restore it to an MBR disk.Finally I had to delete it, convert it and reinstall.
Does anyone know how the development of the GPT is?

saludos

If you add a GPT disk into airboot, it adds MBR record making GPT unusable.
I had this problem and to recover the GPT partition, I used windows tools TestDisk with succes. It found there was an older GPT partition and because I didn't write anything on the disk, this one was elligible for recovery. Once recover was done, GPT was ok and mbr removed.

I have Windows on one disk and ArcaOS on a second disk. Airboot is installed on the ArcaOS boot disk (which has a recovery partition on it with the main OS partition) while windows disk as well my GPT disk are not defined under airboot.  To switch from one to the other, I always use PF11 (select boot disk at startup).

TestDisk is a must tool...
« Last Edit: January 25, 2020, 08:50:15 am by Remy »

Sandra Asja Eickel

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Re: Airboot & GPT
« Reply #4 on: January 25, 2020, 01:41:40 am »
Maybe AirBoot can be extended independently to continue booting from a GPT boot partition on a secondary disk without modifying that disk.


The first thing you might be able to do with a GPT disk is creating a trap dump partition on it :-).
We need a new facility for that as the old one is limited to FAT16 (with a maximum partition size of 2GB) and modern computers have much more RAM than that, used even by our operating system.

But don't expect anything soon - and in a crashed state normal drivers don't work, so this highly experimental GPT support is limited to dumps and has to be extended to LVM/DASD and such and then needs thorough testing.


UEFI boot and XHCI (USB 3.0) support are in beta test now and hopefully end up in 5.0.5 together with the first few NLS versions sometime this year; this feature is way before that stage, perhaps it is presented (if it is further than requiring a system crash) as a sneak preview during WSE or WS US like it had been with UEFI (without CSM) boot to PM with installer to show ongoing research efforts and their results.


So keep your ArcaOS or Driver Subscriptions current and don't forget to send a few sponsor units regularly to BWW, too, to keep our system alive! Progress is not a fast as we all wish, but with those few people behind it, they do deliver a lot and with quality.


Perhaps a different tool like Acronis TrueImage (optionally with universal restore) or DFSee could do the task - there might be registry hacks required to prepare for a change between the two partitioning schemes, also the disk order could require tweaks to the boot config of windows. Just to repeat: Don't try this without a working backup - of both disks!

Sandra-Asja

Doug Bissett

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Re: Airboot & GPT
« Reply #5 on: January 25, 2020, 07:10:33 am »
Quote
Does anyone know how the development of the GPT is?

I believe it is still on the ToDo list, but nobody has done more than look at what might need to be done. Not enough people, who know what they are doing, to do it, and more important things need to be done first.

Quote
If you add a GPT disk into airboot, it adds MBR record making GPT unusable.

The later versions of the LVM engine (in ArcaOS 5.0.4, I believe) will refuse to touch a GPT disk, to prevent problems. That can be overridden, IF you know how. Don't do it, unless you are prepared to lose all of the disk contents. If you still have the older LVM engine, DON'T MESS WITH GPT DISKS.

Quote
Maybe AirBoot can be extended independently to continue booting from a GPT boot partition on a secondary disk without modifying that disk.

It appears, to me, that Air Boot needs to be replaced to support UEFI without CSM support, so it may be possible to do something with it then. Air Boot, as it exists today, barely fits in the space allowed, so expanding it is probably not an option.

Quote
Perhaps a different tool like Acronis TrueImage

Acronis TrueImage is the ONLY windows backup tool, that I know of, that will do backups, and restore to a different disk setup, successfully (it is the ONLY windows backup, that I know of, that actually works as it should). If you have a Seagate, Maxtor, or Samsung disk (even in an external USB drive), you can use the Seagate DiscWizard (search for it). That is a free, limited, version of Acronis. I have used it a few times , while testing ArcaOS installs. While testing, I did install win 10 onto a GPT disk, did a backup, wiped the disk, and restored to it, changing it to be an MBR disk. It worked. YMMV.

Per E. Johannessen

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Re: Airboot & GPT
« Reply #6 on: January 25, 2020, 07:24:30 pm »
Thanks for advises.
However, I used EaseUS Partition Master, Pro-version, and it did convert from GPT to MBR without any issues
and all partitions and data are intact.
Added LVM info to the Win10 partition and Airboot works fine.

Olafur Gunnlaugsson

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Re: Airboot & GPT
« Reply #7 on: January 25, 2020, 08:01:30 pm »
On a system I have two hdd's, one MBR with ArcaOS and one GPT with Win10. Airboot skips GPT disks so it can't boot Win10.
AFAIK the GPT disk has to be converted to MBR for Airboot to see it. Has anyone tried EaseUS Partition Master which claim to keep all data/partitioning on the GPT disk intact, or does anyone have another solution?

I might be misunderstanding this but why do you need to control the boot on the GPT disk via airboot? Why do you not simply use the boot manager built into the UEFI/BIOS and choose GPT/UEFI or BIOS/MBR on startup as needed?

Per E. Johannessen

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Re: Airboot & GPT
« Reply #8 on: January 25, 2020, 11:58:07 pm »
I'm going to have a "shared" partiiton on the Win10 disk and I would not be able to access it from ArcaOS if it was not converted to MBR.