Partition Layout UEFI Dual Boot

**SPfliegel** · 30-Oct-2017, 07:20

Hey there,

I'm trying to install Tumbleweed as my second OS (next to Windows 10) and I'm currently confused about the partition setup. For the last PC I installed (3 years ago) I still used the good old MS-DOS partitioned / MBR / BIOS style, though UEFI and GPT was already established. This time I wanted to move to UEFI (without Secure Boot). Windows is already installed and the existing partitions don't occupy the whole drives.

Here's the desired setup:
sda1: Windows reserved partition
sda2: EFI partition
sda3: Windows reserved partition
sda4: Main Windows partition
sda5: Tumbleweed BtrFS /
sdb1: Windows Home/Data partition
sdb2: Tumbleweed Swap partition
sdb3: Tumbleweed home partition XFS /home

I'm a bit confused about the EFI partition. I read that I need to mount it to /boot/efi or is it /boot? The partition needs no formatting,right? Otherwise I asume I'd loose the Windows 10 bootloader. Is there something else that I need to consider?

I'd like my Windows 10 to boot per default (without GRUB) and if I want to boot openSUSE I want to do it via the UEFI boot menu.

**nrickert** · 30-Oct-2017, 07:50

Your desired setup looks okay.

Yes, you use the existing EFI partition (the one used by Windows). And do not format it.

The EFI partition is to be mounted at "/boot/efi".

General rule of thumb:

Mount EFI partition at "/boot/efi" if using grub2.
Mount at "/boot" if using systemd boot or other variations of gummiboot.

OpenSUSE, Ubuntu, Mint, Fedora all use grub2.

**nrickert** · 30-Oct-2017, 07:58

Originally Posted by SPfliegel

I'd like my Windows 10 to boot per default (without GRUB) and if I want to boot openSUSE I want to do it via the UEFI boot menu.

Oops! I missed that part in my first response.

UEFI implementations vary. Some will give you headaches, but most work properly.

After installing openSUSE, your system will boot to the openSUSE grub2 menu. You can possibly change that in your firmware (BIOS) settings. Or it is easy to change from within opensuse.

Use the following commands as root:

Code:

efibootmgr

(or add a "-v" for more information).

That should give you a list of the boot options, with a 4 digit number for each. And it should tell you the boot order.

You can change the boot order. Assuming that Windows is 0000 and openSUSE is 0001, your boot order will show as 0001,0000

To change, use

Code:

efibootmgr -o 0,1

This will put boot 0000 first, and 0001 second. Your numbers might be different.

**gogalthorp** · 30-Oct-2017, 10:45

Since it is hard to boot to Linux from Windows (you can use UEFI boot menu) and easy to boot to Windows from Linux it is best to allow grub to control the machine booting. You can set the default OS in YAST BootLoader

**SPfliegel** · 02-Nov-2017, 01:05

That did the trick! The first couple of times I tried I always received weird warnings and luckily I hesitated to simply ignore them. I figured that I booted the USB-stick in legacy mode instead of UEFI. That's why the openSUSE installation didn't recognize my UEFI boot layout.

Changing the boot order with efibootmgr also worked like a charm! Thanks a lot guys!