uefi images: "error: no such device: root."

[dann frazier]

I noticed when booting an arm64/artful image, I've started seeing the error:

----------------------------------------------------
error: no suitable video mode found.
error: no such device: root.

Press any key to continue...
----------------------------------------------------

The "no suitable video mode found" error has always been there, but the "no such device: root." and "Press any key to continue..." messages appear to be new. Obviously, having to press a key to continue would be a real problem for a cloud environment - but, the boot does appear to continue w/o a key press anyway.

[dann frazier (dannf)]

Also reproduced with http://cloud-images.ubuntu.com/xenial/current/xenial-server-cloudimg-amd64-uefi1.img

[dann frazier (dannf)]

changed bug title, since this isn't an ARM-specific issue

[Gustavo Niemeyer (niemeyer)]

Has anyone found a way to workaround this problem?

[dann frazier (dannf)]

The problem is apparently "only cosmetic", since the boot proceeds anyway, but it really would be nice to fix as it impacts both x86 and ARM uefi images.

[Robert C Jennings (rcj)]

It is cosmetic but there is work to address this. Work was blocked on release since we were too close to GA. The change will impact all cloud-images so this requires extensive testing, so I do not have an ETA for a fix.

[Gerry Boland (gerboland)]

I've encountered this too, tracked it down to a problem in the root filesystem's grub.cfg, it contains the line

 search --no-floppy --fs-uuid --set=root

which is incorrect - there should be a UUID appended to this line. Since there isn't, grub tries to find a device with uuid "root" which fails, and it complains.

[evilhamsterman (evilhamsterman)]

To expand on the previous comment, the issue can be resolved post boot by running update-grub which will fill out the missing values on the search line. It appears the build process is either not running update-grub or it is using a default grub template that is missing the appropriate data.

[Mathieu Trudel-Lapierre (cyphermox)]

This is strictly an image build issue; livecd-rootfs diverts all of grub-probe in the divert_grub() function, but it really should only do this for 30_os-prober.

We already run update-grub correctly; the issue is that some of these calls may happen with grub-probe diverted in such a way that the grub.cfg will get mangled a bit, dropping the right path for the search command used to find the root.

[dann frazier (dannf)]

I saw this pop up again in a lxd --vm demo yesterday - any chance we can get it addressed this cycle? :) Happy to help w/ the testing where possible..

[fraser addison (fraseraddison)]

When I set admin_pass: <password> in coud meta file it disapeared. This is a local run in kvm.

[Dion Bosschieter (dionbosschieter)]

I also experience this using the bionic cloudinit image:

https://cloud-images.ubuntu.com/bionic/current/