[Solved] Converting from BIOS+Grub1+MBR to UEFI+Grub2+GPT

PhotonX · 2013-03-01 08:29:07

Hello community,

my motherboard has an annoying bug, the POST sometimes taking over 20 seconds. Now I noticed that my motherboard is actually in the BIOS legacy mode, while UEFI mode is available. So I'd like to switch to UEFI in the hope that the BIOS bug won't appear there. I've read through several Wiki pages and forum posts, but still don't really know how to proceed.

The current setup is: The motherboard is in BIOS legacy mode, an HDD and an SSD are connected. The HDD contains just a big data partition while the SSD contains /, /home and swap. Grub1 is installed in the MBR of the SSD.

As far as I have understood from the Wiki, I need to change the partition table to GPT before switching to UEFI. According to https://wiki.archlinux.org/index.php/GP … MBR_to_GPT it is even possible without data loss. Since I need to free 1MiB at the end of the partition table, I'd need to boot some Live-USB and perform all the operations from there. So my first question is: If I change to GPT from Live-USB, will Grub1 still be able to boot the system afterwards?

Second thing is, I've noticed that Grub1 is neither present in the repos, nor in the AUR any more. So if I uninstall it and something goes wrong, how to get Grub1 back?

Thanks for any help,
Photon

Last edited by PhotonX (2013-03-01 12:09:16)

swordfish · 2013-03-01 09:31:36

PhotonX wrote:

my motherboard has an annoying bug, the POST sometimes taking over 20 seconds. Now I noticed that my motherboard is actually in the BIOS legacy mode, while UEFI mode is available. So I'd like to switch to UEFI in the hope that the BIOS bug won't appear there. I've read through several Wiki pages and forum posts, but still don't really know how to proceed.

Try a live-medium that starts in UEFI-mode. The easiest way would be using the latest Ubuntu. If you've switched your BIOS from legacy boot to UEFI first, Ubuntu should detect this and start in UEFI mode. So you could check if it solves your POST problem.

If you want to try it with the latest Arch-ISO just follow the wiki for creating a UEFI bootable usb device. After booting this device, check if it really has booted in UEFI-mode

PhotonX wrote:

Second thing is, I've noticed that Grub1 is neither present in the repos, nor in the AUR any more. So if I uninstall it and something goes wrong, how to get Grub1 back?

You can't (unless you are using an old Mac) . If you want UEFI and Grub, use grub-efi-x86_64.

swordfish · 2013-03-01 09:38:28

PhotonX wrote:

So my first question is: If I change to GPT from Live-USB, will Grub1 still be able to boot the system afterwards?

Don't think so. Have a look: https://wiki.archlinux.org/index.php/GP … er_Support

GRUB Legacy, present in the AUR as grub-legacy, does not support GPT disks.

PhotonX · 2013-03-01 12:07:21

Thanks, I tried the Ubuntu-Iso and have realized that the difference between legacy BIOS and UEFI comes into play only after the mainboard logo is displayed, which is after the bug appears. So a switch to UEFI doesn't make sense, I suppose. But on the other hand while playing around with the boot priority I noticed that the problem is gone if the SSD is on the first place in the boot list (rather then the USB key). Since I almost never boot from USB, I just put the SSD to first priority and got rid of the problem.

Thanks for your assistance,
PhotonX

Last edited by PhotonX (2013-03-01 12:08:09)

Arch Linux

#1 2013-03-01 08:29:07

[Solved] Converting from BIOS+Grub1+MBR to UEFI+Grub2+GPT

#2 2013-03-01 09:31:36

Re: [Solved] Converting from BIOS+Grub1+MBR to UEFI+Grub2+GPT

#3 2013-03-01 09:38:28

Re: [Solved] Converting from BIOS+Grub1+MBR to UEFI+Grub2+GPT

#4 2013-03-01 12:07:21

Re: [Solved] Converting from BIOS+Grub1+MBR to UEFI+Grub2+GPT

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