I have 2 SSDs in my laptop. On 1 have EndeavourOS as my daily driver, and on the other I want to install CachyOS. So, this is a different, separated dual boot rather than have 2 OSs on the same drive.
During the boot process I want to be able to choose which OS will be booted into, rather than open the BIOS and change the boot order.
From what I have read, CachyOS’s installer may overwrite the EndeavourOS EFI partition and bootloader entries, potentially removing access to EndeavourOS if it uses systemd-boot, which it does in my case.
So, is there a way to get the choice between EOS and COS without have to dive into the BIOS each time?
Seems logical alright. Making them share an EFI partition means during Cachy’s installation I have to manually create partitions, one of which will be an EFI partition, for which I choose EOS’s EFI partition. Correct?
Calamares should always try to re-use your existing ESP, even when you use automatic partitioning unless Cachy has done some customization there. You can easily check that, it will show you that in the partition module before it has taken any action.
Just boot off the Cachy ISO and see what it wants to do.
I just did this with CachyOS and Void linux. When you install CachyOS, select rEFInd as the boot manager you want to install. It’s the first question on their installer. The installation should proceed, and rEFInd will find your EndeavourOS installation as well as become the default boot loader. When you reboot, you will be greeted by the rEFInd screen and can select your OS (via keyboard arrow keys, no mouse in default config but that can be added).
Yeah, if you install systemd-boot into the same ESP, it will “just work”.
That is the beauty of systemd-boot, there is no detection. Each OS writes and maintains it’s own entries in a single bootloader. It will probably overwrite the EOS systemd-boot with the Cachy version but it doesn’t really matter. You will not notice the difference since systemd-boot is basically all the same. It just reads the entries in loader/entries and both OSes will write their entries to the same place.
When I boot up the computer, will both OSes be shown as options to be chosen from, and if I at that point I sit back and don’t make a choice it will boot into the primary OS which will then be CachyOS?
You may need to set CachyOS as the default in loader/loader.conf unless CachyOS already is the default(Which it might be due CachyOS being lower alphabetically)
Many thanks for your help. I am going to try to do this, and will let you know how I fare, which might also be useful for others too who are considering a 2-drive dual boot.
@dalto I have been able to successfully install CachyOS on the other SSD. I did, however, install it with the rEFIned boot loader because I did not like the idea of COS overwriting the EOS boot.
The issue I am faced with now is that when I boot up, the regular EOS boot loader is shown with only EOS as an “option”. I cannot change the boot loading sequence in my BIOS so it shows Refined with the 2 options EOS and COS.
But in the BIOS there is a so-called BBS Menu, which shows both EOS and Refined. If I click on Refined it opens it up, and sure enough both EOS and COS are shown as options. Clicking on EOS boots to EOS, clicking on COS boots to COS. Like I indicated, I cannot get it to make Refined the primary boot loader.
Someone has suggested to me to remove the boot flag from EOS’s EFI partition. That way, when I fire up my computer, only Refined will be detected and thus presented. What is your take on that?
Boot0005* UEFI OS HD(1,GPT,e9a22f70-9ae4-4f37-bd27-b64de1d8fb7a,0x1000,0x200000)/\EFI\BOOT\BOOTX64.EFI0000424f
Then I tried to change the boot order by typing sudo efibootmgr -o 0001,0000,0005, which seems to change the boot order. But when I reboot, it is EOS again that launches, and sudo efibootmgr -v shows that 0000 is still the primary.
What is it you don’t like about removing EOS’s EFI partition boot and/or esp flags?
