Is there a step-by-step guide for converting bios install to uefi?

My current system is installed in bios mode and I would like to convert it to a uefi install without losing data. Can anyone provide me with a step-by-step guide? Thanks in advance!

See if this can get you started.

If not try the search function. bios grub uefi

Do you have already an existing EFI partition? Because that’s the most “difficult” part of it, I think. If not, you have to create one and add it to the fstab file.

Other than that, it’s mostly a normal grub restore procedure using the live installation media (you can use one of the dozens guides that people has made for Manjaro).

Looks like I’ll have to create an ESP, I don’t have one on my system.
Also most of the guides assume that my disk is formatted using GPT. My system is using MBR…So I’m not sure how to proceed.

Converting MBR to GPT can be done easily with gdisk. For the ESP… yes, as I said that’s the difficult part, as you probably have to resize one of your partitions. Linux doesn’t need to much space for EFI boot, so if you have a swap partition, maybe you can spare 50 - 100MiB for ESP (FAT32 and boot flag). You also have to remember to add it to the fstab with mount point /boot/efi.

Once you have that, it’s a matter of reinstall grub using any rescue procedure for Manjaro you can find.

Edit: About gdisk, I’m not sure how safe it is, but IMO it should work. See, for example:

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Now came to my mind, that you have to do everything in one go. Once you convert to GPT, your Manjaro is not going to boot (as bios boot over GPT needs an additional grub-bios partition). Just be advised.

There’s a step by step guide in the wiki, I used it last year

Out of curiosity, did the mbr-gpt conversion process create extra partitions on your disk?

I don’t think so.

If you want to convert a legacy boot to EFI boot - the system disk must be partitioned using GPT.

If it is not - you will have to repartition and format the disk.

While the gpart utility can convert MBR to GPT - the likelyhood of dataloss is possible - thus not recommened unless you have safeguards in place - something like either backing up valuable files or a diskimage using clonezilla (because clonezilla images are smaller than dd’ed images)


I’ve successfully converted my laptop from bios to uefi a couple of months ago.
No dual boot of course.
And with Arch on it, but that shouldn’t matter.

I’ve checked your link and it seems promising. My only question now concerns the location of the EFI system partition: is there any way to put it at the start of the disk?

That doesn’t matter, you may place it at the end.

Won’t having an ESP at the end of the disk mean I have to move it every time I add storage?

Sorry, what do you mean? When you add storage, how? Another disk?

Yes, by adding another SSD/HDD

When you add another disk, you don’t need to change anything from the first disk.

Alright, I’ll give this a shot in the next few days (hopefully tomorrow). I’ll report back if I encounter any issues.

It worked! Thank you guys! Device is running on GPT+UEFI now!
Documenting my experience in case someone else might want to make the jump: I was surprised how fast and clean the mbr-gpt conversion was-it only took a second. I had to boot off of a manjaro ISO so I could modify the partitions with gparted. I also managed to make space for the ESP at the front of the disk by shrinking and moving my old partition.
Installing grub required some messing with chroot, but shouldn’t be too hard if you follow the manjaro wiki.
One last question before signing out: in /etc/fstab what should I write in the “options” section for the ESP?

Just defaults should be OK. Other distros have their own policy of handling $esp.
For instance, Ubuntu and Fedora use umask=0077 in order to make all files on this partition inaccessible to a regular user. This makes it impossible to view its files with, say, Dolphin file manager, but sudo commands work fine.