I'm booting from NVME but I want to switch back to eMMC

[acruhl]

These are the rough steps I took to get where I am:

1. Started with Manjaro working fine from eMMC
2. Installed NVME disk
3. Copied eMMC to NVME (using dd)
4. Installed tow boot to SPI
5. Booted, interrupted boot and chose NVME

This worked. However, now I want to boot from eMMC again. I rebooted and chose the eMMC option in tow boot, but it doesn't work.

I now have /boot mounted from the eMMC and / mounted from the NVME.

I used blkid and noticed that the UUID for my eMMC partitions and my NVME partitions are the same (because they would be, I copied form eMMC to NVME) and I assume this has something to do with my problem.

What should I do to boot from eMMC where / is also mounted from the eMMC?

I have thought of:

1. Physically removing the NVME disk
2. Using dd to wipe out the NVME disk

But I'll wait for an answer.

(I booted Fedora on a MicroSD to type this, this works fine.)

Thanks.

[acruhl]

Replying to myself.

Unplugging the NVME and choosing eMMC from tow boot worked.

Another issue I forgot to mention: I was getting panics with the NVME. Or so I assume, the power led was flashing between red and green. I'll look into the steps to mitigate problems with NVME disks.

I'm going to try to install a different OS to the NVME, we'll see how that goes. I'm just hoping I can really choose between them with tow boot. I assume it will work.

[diederik]

I used blkid and noticed that the UUID for my eMMC partitions and my NVME partitions are the same (because they would be, I copied form eMMC to NVME) and I assume this has something to do with my problem.

Yes it does and you should fix that. Universally Unique IDentifiers need to be unique. The value they have is not important, but the unique-ness is.

[wdt]

Maybe you already know......
man tune2fs ; tune2fs -l <device> ; tune2fs -U time <device>
where device = some partition with an ext fs on it
(of course edit fstab with new UUID)

[acruhl]

Maybe you already know......
man tune2fs  ;  tune2fs -l <device>  ;  tune2fs  -U time <device>
where device = some partition with an ext fs on it
(of course edit fstab with new UUID)

Yes, I did find that. Thanks. My goal was not to run Manjaro on the NVME, or not yet anyway. I just wanted to boot from it. 

The reason I didn't just keep it that way was I had a few kernel panics when booted from the NVME and I haven't gone through all the advice on how to set up the NVME disk yet.