21.04 Panics attempting to boot 5.10.0-3.4 in gcp EFI disk

[Sean Feole]

This was caught while testing a few runs in the google cloud.
Steps to reproduce:
1.) deploy 21.04 in the cloud (n1-standard-1 instance type)
2.) install 5.10.0-3.4 from the canonical-kernel-team bootstrap ppa
2a.) sudo add-apt-repository ppa:canonical-kernel-team/bootstrap
3.) sudo apt install linux-generic-wip
4.) update grub to boot the generic kernel as the default kernel will be -gcp, (use attached script comment#4) ./script.sh generic
5.) reboot and monitor console logs

Full startup logs attached:

looks to be grub related, I have not looked into this any further.

   1.410153] VFS: Cannot open root device "PARTUUID=02631d3d-a298-4349-b157-aa86d82843b5" or unknown-block(0,0): error -6
[ 1.411882] Please append a correct "root=" boot option; here are the available partitions:
[ 1.413203] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
[ 1.414356] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.10.0-3-generic #4-Ubuntu
[ 1.415702] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 1.417180] Call Trace:
[ 1.417710] show_stack+0x52/0x58
[ 1.418263] dump_stack+0x70/0x8b
[ 1.418738] panic+0x101/0x2e3
[ 1.419209] mount_block_root+0x21e/0x298
[ 1.419778] mount_root+0x38/0x3a
[ 1.420243] prepare_namespace+0x13f/0x18d
[ 1.420840] kernel_init_freeable+0x156/0x17d
[ 1.421574] ? rest_init+0xba/0xba
[ 1.422135] kernel_init+0xe/0x116
[ 1.422708] ret_from_fork+0x22/0x30
[ 1.423858] Kernel Offset: 0x10c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[ 1.425374] ACPI MEMORY or I/O RESET_REG.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1904243

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Francis Ginther (fginther)]

I was not able to reproduce this:

ubuntu@fginther-hirsute:~$ lsb_release -c
Codename: hirsute
ubuntu@fginther-hirsute:~$ uname -a
Linux fginther-hirsute 5.10.0-4-generic #5-Ubuntu SMP Mon Nov 16 09:45:27 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
ubuntu@fginther-hirsute:~$ cat /etc/cloud/build.info
build_name: minimal
serial: 20201114

I booted a minimal hirsute image by mistake, but it should be close. Also, the kernel was up to 5.10.0-4 when I tested.

There could still be some compatibility issue in play here. Let's see how the next round of testing goes.

[Sean Feole (sfeole)]

use the attached script to change the boot kernel ,
usage: ./script.sh generic

[Francis Ginther (fginther)]

This is likely the same underlying root cause as https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1901633. The system is failing to fallback to the initrd path and therefore gets stuck in a reboot/panic loop.