since im not 100% sure of the boot sequence and files… is it possible to have 2 versions of opensuse e.g. TW and 15 or even 2*TW?
i ask this since if i look in /boot/efi/EFI/ i see TW registerd as opensuse which suggests non uniqueness?
if anyone could clarify the relation between /boot/efi and the efi partition that would be appreciated.
The EFI partition is used by the system “firmware” during boot.
The partition is mounted on /boot/efi on your running openSUSE to have it available for consulting it’s contents, changing it’s contents, etc.
so the efi partition is mounted on /boot/efi.
so if TW is designated simply as ‘opensuse’ (and assuming the same for leap) then how can 2 different version of opensuse be installed on the same machine without overwriting each other?
Yes, it is possible.
I currently have:
- openSUSE Leap 42.3]
- openSUSE Tumbleweed
- openSUSE Leap 15.0 Beta
on three different computers. And one of those also has a second install of Tumbleweed.
One of those computers is for legacy booting. The others use UEFI booting.
I recently (December) blogged about how I am handling that with UEFI:
Handling multiple openSUSE version with UEFI
Perhaps you might find that useful.
> nrickert
thanks! but after reading, changing GRUB_DISTRIBUTOR actually sounds much easier? and since i could then set grub to boot disto by name rather than the first in the list, the default would not change after an update. what is the downside of this method?
It depends on your UEFI firmware (otherwise known as BIOS).
On one of my UEFI boxes, that works well. On the other, the BIOS thinks that I have too many UEFI system names, and deletes one of them.
Why use UEFI booting? My disks are:
erlangen:~ # parted -l
Model: ATA WDC WD40EZRX-22S (scsi)
Disk /dev/sda: 4001GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Disk Flags: pmbr_boot
Number Start End Size File system Name Flags
1 1049kB 8389kB 7340kB primary bios_grub
2 8389kB 34.4GB 34.4GB linux-swap(v1) primary msftdata
3 34.4GB 68.7GB 34.4GB ext4 primary legacy_boot, msftdata
4 68.7GB 4001GB 3932GB ext4 primary msftdata
Model: ATA KINGSTON SV300S3 (scsi)
Disk /dev/sdb: 60.0GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:
Number Start End Size Type File system Flags
1 1049kB 30.1GB 30.1GB primary ext4 boot, type=83
2 30.1GB 60.0GB 30.0GB primary type=83
Model: NVMe Device (nvme)
Disk /dev/nvme0n1: 512GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:
Number Start End Size Type File system Flags
1 1049kB 34.4GB 34.4GB primary linux-swap(v1) type=82
2 34.4GB 68.7GB 34.4GB primary ext4 boot, type=83
3 68.7GB 512GB 443GB primary ext4 type=83
erlangen:~ #
Grub creates a nice boot menu with the following entries:
erlangen:~ # grep menuentry /boot/grub2/grub.cfg | cut -f 2 -d \'
**...
openSUSE Tumbleweed**
Erweiterte Optionen für openSUSE Tumbleweed
openSUSE Tumbleweed, mit Linux 4.15.4-1-default
openSUSE Tumbleweed, mit Linux 4.15.4-1-default (Wiederherstellungsmodus)
openSUSE Tumbleweed, mit Linux 4.15.3-1-default
openSUSE Tumbleweed, mit Linux 4.15.3-1-default (Wiederherstellungsmodus)
** openSUSE Tumbleweed (auf /dev/sda3)**
Erweiterte Optionen für openSUSE Tumbleweed (auf /dev/sda3)
openSUSE Tumbleweed (auf /dev/sda3)
openSUSE Tumbleweed, mit Linux 4.14.5-1-default (auf /dev/sda3)
openSUSE Tumbleweed, mit Linux 4.4.79-19-default (auf /dev/sda3)
** openSUSE Tumbleweed (auf /dev/sdb1)**
Erweiterte Optionen für openSUSE Tumbleweed (auf /dev/sdb1)
openSUSE Tumbleweed (auf /dev/sdb1)
openSUSE Tumbleweed, mit Linux 4.15.3-1-default (auf /dev/sdb1)
openSUSE Tumbleweed, mit Linux 4.14.12-1-default (auf /dev/sdb1)
erlangen:~ #
Why not?
Yes, I agree that grub2 does a pretty good job of creating a boot menu. And GPT partitioning seems to work well, even on machines with a legacy BIOS. But UEFI is the future.
As you probably have heard by now: Yes, of course you can dual boot two versions of openSUSE.
I currently have on laptop that is Quadra-Booting openSUSE 13.2, openSUSE 42.2, openSUSE 42.3, and AV Linux (a Debian-GNU-based Music/Media Production specialty distro with a Zero Latency kernel).
Other machines are various combinations, and the one I am typing this message on is going to be Quadra-Booting with test installs of Tumbleweed and the testing phases of Leap 15 starting within the next day or two, along with the already-installed and running 42.3 and AV Linux.
… so, I think it is possible. 
Ooooh! Scary!!!
… unless, of course, the hardware manufacturers can get their act together and co-operate to follow a good, solid standard.
Something they have not been able to do in more than 50 years, BTW.>:)
> Fraser_Bell
could you say which method you use to prevent overwrite of the file in the default folder ‘opensuse’ and how you keep default boot from changing on updates?
I do not have any UEFI setups on any of my machines.
The main reason for that is most are (some very) old machines.
Your best bet is to follow nrickert’s advice, and perhaps other UEFI users, if you are using it.
Other than that, I am not sure you understand the Grub bootloader and how it works, or I do not understand this question, as I have no such issue.
Keeping default boot from changing on updates? My best answer to that, if I correctly understand what you are asking, is to not install Grub to the MBR.
Instead, install the bootloader to its own root partition.
Use generic MBR.
Set the active flag on the one version you want controlling Grub. The OS Prober in the Bootloader module will find the other installed Operating Systems (and/or other versions of openSUSE) and will list all of them in the Grub menu on separate lines.
Sure, but future will have to wait until some compelling reason for change emerges. 
https://forums.opensuse.org/showthread.php/529610-How-do-I-eliminate-UUID-dependence explains how I deal with boot selection priority on my only UEFI PC. 
I have:
/etc/default/grub:GRUB_DEFAULT=saved
/etc/default/grub:GRUB_SAVEDEFAULT=“true”
/boot/grub2/grubenv:saved_entry=openSUSE Tumbleweed
Since install Grub 2 never changed defaults.