If you're using an XPS 7590 laptop with its own security OS, you may encounter a frustrating error that prevents you from booting into Ubuntu. In this post, I'll explain the error message I saw and the steps I took to fix the problem and get Ubuntu working again.

The Error Message

I couldn't boot into Ubuntu, it showed an error and ended up opening a terminal named initramfs. I tried to exit the terminal but it showed an error:

Gave up waiting for root device. Common problems:
 - Boot args (cat /proc/cmdline)
   - Check rootdelay= (did the system wait long enough?)
   - Check root= (did the system wait for the right device?)
 - Missing modules (cat /proc/modules; ls /dev)
ALERT! /dev/disk/by-uuid/920903aa-762f-40d2-8126-87f4b0e6f975 does not exist. Dropping to a shell!

BusyBox v1.19.3 (Ubuntu 1:1.10.3-7ubuntu1.1) built-in shell (ash)
Enter 'help' for a lost of built-in commands.
(initramfs)

This message indicates that the Ubuntu system was having trouble finding the root device it needed to boot up.

The Cause

After investigating further, I discovered that the error was caused by a change in the laptop's boot sequence and SATA operation settings. Specifically, when the laptop crashed, the boot sequence was switched by Support Assist from Ubuntu first to first Windows, and the SATA operation settings were changed from AHCI to RAID on. This led to the error message when trying to boot into Ubuntu.

The Solution

To fix the error, I needed to change the SATA operation settings back to AHCI.

Here's how I did it:

1. Restart the laptop and enter the BIOS settings by pressing the F12 key.

2. Go to BIOS Setup.

3. Navigate to the SATA Operation setting and change it from RAID on to AHCI.

4. Save and exit the BIOS settings.

5. Reboot the laptop and try booting into Ubuntu again.

After making this change, Ubuntu booted up without any problems and I was able to use it normally.

Conclusion

If you encounter a similar error message when trying to boot into Ubuntu, don't panic! It's likely caused by a change in the boot sequence and SATA operation settings but can be easily fixed by changing the SATA operation back to AHCI in the BIOS settings. By following these steps, you should be able to get Ubuntu working again and avoid further frustration.