Reinstalling 'Nadia' via EFI

[oldhack]

This may be a 'dumb' question to an expert, which I am not!
I would like to reinstall 'Nadia' on a gpt setup (- I am able to reset my efi/bios to EFI), and I have taken a 'cloned' backup image
of a second OS that I had installed on a bios partition but now wonder if the cloned bios partition can actually be recovered to a GPT drive setup.

I would appreciate some advice on this?

o.

[viking777]

wonder if the cloned bios partition can actually be recovered to a GPT drive setup.

Interesting question. The only thing I can tell you for certain is that I have done it the other way around. That is, imaged a distro installed on a gpt, Uefi machine and restored it onto a non-gpt, non-uefi one and it worked perfectly. It took a little time to think about it the first time it booted up, but it did so and still runs normally today. The only proviso I would add to that is that my Uefi machine contains one of those horrible 'hybrid' firmware installations where you can't select one or the other, it just selects for you. This may make a difference in that I have both types of firmware on my 'donor' motherboard, legacy and uefi, and you may not have that.

Thinking about the science of it (which I have a very high chance of getting wrong ) If you create an empty partition on your gpt machine first, then the guid partition table will be aware of the partition before you clone to it, so that shouldn't be a problem. The boot aspect of it will depend on the OS you are cloning. In my experience most modern distros have both legacy and Uefi boot files so if it has both, and you run 'sudo update-grub' on the gpt machine then in all likelihood grub will pick up the legacy files on the cloned distro and add those to the boot menu. If that doesn't happen but /boot/grub on the cloned distro contains xxxxx.efi files then you could probably boot those by copying then to your efi system partition (they have to have their own folder on that partition - look at the structure of an existing entry and copy its format). I have done this myself and it worked for me.

In closing I would say this. A little knowledge is a dangerous thing, and a little knowledge is exactly what I have on this subject - caveat emptor!!

Edit. Although I don't think you will cause any damage by just trying this, it might be a good idea to have a 'whole disk' image to fall back on just in case I am wrong. Clonezilla would do this for you if your existing software doesn't. Btw, It gladdens my heart to see that you are one of the enlightened few on this forum that realise the immense benefits that cloned images bring

Edit2. Just to check, you do realise that gpt (which is extremely valuable) and Uefi (which is extremely irritating, useless and in some cases dangerous) do not have to go together. You don't have to have Uefi in order to have gpt. That is the situation I have now, a legacy boot with a gpt partitioning scheme. Due to the lack of control in my bios settings this was not at all easy to achieve, but in your case it is - just switch to legacy mode and leave it there, install everything in that mode and never think about Uefi again. That would be my recommendation to anyone using Linux on Uefi. Of course if you use windows as well, and that has been installed in Uefi mode, then the process is more complicated because you would have to reinstall windows in legacy mode for everything to work, and probably if you have windows 8 this is impossible.

[oldhack]

Thank you for your prompt response and insight.
I will follow your advice and take a full HDD clone image before I do anything!
I will then set up a GPT partition and reinstall. I am a little apprehensive about doing this because of my lack of experience however, I do not have a Windows OS
on the machine (I completely 'wiped' the monstrosity 8 off the drive) - so here goes.

o.

[srs5694]

I would like to reinstall 'Nadia' on a gpt setup (- I am able to reset my efi/bios to EFI), and I have taken a 'cloned' backup image
of a second OS that I had installed on a bios partition but now wonder if the cloned bios partition can actually be recovered to a GPT drive setup.

Yes, but:

• Depending on your cloning software, it might try to re-create a Master Boot Record (MBR) partitioning system; but EFI-based computers almost always boot from GUID Partition Table (GPT) disks. Thus, you'll need to understand this difference, and your software's capabilities, well enough to ensure that you create a GPT setup on your new disk. You'll also need to have an EFI System Partition (ESP) on the new disk.
• You'll need to install an EFI boot loader for the new system. (Follow that link for information on what's available and how to set it up.)

Doing this shouldn't really be much harder than restoring a backup to a BIOS-based system, in the sense that the utilities you use and commands you type will be very similar. The trouble is that the commands are different, and few people have the expertise to know precisely how they're different. There's also the fact that EFIs vary a great deal from one to another, and some are buggy, so you can run into system-specific problems. Thus, as a practical matter, most people with any experience with BIOS-based systems will find what you're attempting to be harder than restoring a backup to a BIOS-based system. My best advice on this score is to read up before you try anything and then to post back with questions if you run into problems.

[oldhack]

Thank you srs5694, for your respose.

I regret that my effort had inconclusive results. I used the wrong 'cloning' s/w at least whilst cloning the complete drive, it 'froze' the "idiot" (laptop) after about 60%
(-about an hour!) I did not have the time to retry so I took an existing cloned image (a single bios partition) previously put on a usb hdd, of what was just a second o/s from the main HD.
After setting up a my efi boot loader and nadia on the gpt drive I tried to recover my second o/s from the usb drive. The recovery s/w just wanted to completely wipe the gpt and 'plaster' the bios partition over the complete drive!
I am wondering if the 'bios reserved grub partion' that is of course missing from a non-efi bios partion, had any effect in this?

When I have more time I intend to try again but using 'Clonezilla'.

Thanks again for your interest and help

o.