Dual Boot with Ubuntu

I was thinking of Dual booting Clear and Ubuntu. I read through the instructions and it seems a tad complicated. I have 2 drives one for each OS… I assume the instructions stay the same? Is there anything in the works to ease this process? Just curious.

I have this set up on one of my machines and use the BIOS boot manager to select the drive to boot to. One for Windows and one for Linux. That’s as simple as it gets. Not sure what BIOS you have but there is normally a specific Fn key to press to call up the BIOS boot manager. Select the drive you want and boot.

So your doing it directly from the setup menu of the bios you mean?

Yes, when I have two separate HDDs, each with its own image, that’s the cleanest way.

You can load Ubuntu from systemd-boot, see How to recover grub after installing Clear Linux OS?

While I don’t know about the 2 HDD.
I have installed tri-boot with Windows, Ubuntu and Clear Linux OS.
The instructions say to install Clear first, but I didn’t want to start over with my other 2 installs.
From the start I installed Windows, then installed Ubuntu 19.04, then I installed Clear Linux OS all on 1 drive 3 partitions. You can either A: Use BIOS to boot to the OS you want. or B: boot into Ubuntu, add the PPA for “boot-repair”(PPA:yannubuntu/boot-repair) install boot-repair, run boot-repair, then it will add the Clear Linus OS to the Grub menu. You will also need to download Grub-customizer because the repair will add several useless entries for Ubuntu and Clear Linux, so Grub-customizer will let you remove all the un-needed entries. You’ll be able to select what OS you want from Grub during boot.

But like I said, I haven’t tried this on 2 HDD, just one my single ssd laptop.
If you installed Ubuntu first on one drive, the Clear Linux OS live installer option should detect both drives where you can select either of them. Then you can do either A or B as I described above.

Hope this helps.