Mauricio, Interesting update, I agree that we need more info as to what the state is when the instance won't boot switching to the new 4.15 kernel. I'll check with my team in the morning and see if we can get additional info from AWS
I was trying a few more scenarios this evening the first being the most interesting. Scenario 1 start with 5.4.0-1056-aws install 5.4.0-1058-aws reboot confirm 5.4.0-1058-aws booted reboot AGAIN install 4.15.0-1113-aws reboot machine booted 4.15.0-1113-aws successfully Scenario 2 start with 5.4.0-1056-aws install 4.15.0-1112-aws reboot install 4.15.0-1113-aws reboot confirmed 4.15.0-1113-aws booted then booted back into 5.4.0-1056-aws removed 4.15.0-1112-aws and 4.15.0-1113-aws rebooted again for good measure confirmed still running 5.4.0-1056-aws installed 4.15.0-1113-aws rebooted 4.15.0-1113-aws successfully loaded -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-aws in Ubuntu. https://bugs.launchpad.net/bugs/1946149 Title: Bionic/linux-aws Boot failure downgrading from Bionic/linux-aws-5.4 on r5.metal Status in linux-aws package in Ubuntu: New Bug description: When creating an r5.metal instance on AWS, the default kernel is bionic/linux-aws-5.4(5.4.0-1056-aws), when changing to bionic/linux- aws(4.15.0-1113-aws) the machine fails to boot the 4.15 kernel. If I remove these patches the instance correctly boots the 4.15 kernel https://lists.ubuntu.com/archives/kernel- team/2021-September/123963.html With that being said, after successfully updating to the 4.15 without those patches applied, I can then upgrade to a 4.15 kernel with the above patches included, and the instance will boot properly. This problem only appears on metal instances, which uses NVME instead of XVDA devices. AWS instances also use the 'discard' mount option with ext4, thought maybe there could be a race condition between ext4 discard and journal flush. Removed 'discard' from mount options and rebooted 5.4 kernel prior to 4.15 kernel installation, but still wouldn't boot after installing the 4.15 kernel. I have been unable to capture a stack trace using 'aws get-console- output'. After enabling kdump I was unable to replicate the failure. So there must be some sort of race with either ext4 and/or nvme. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-aws/+bug/1946149/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
