Grub takes over 2 minutes to load kernel

[js1]

Kubuntu 20.04 grub2 is taking 2m12s to load kernel after kernel has been selected. Similar to expired #577120. Didn't seem to have this problem on Lubuntu 20.04. Once kernel does load (after long delay), boot seems normal.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: grub-pc 2.04-1ubuntu26.15
ProcVersionSignature: Ubuntu 5.15.0-43.46~20.04.1-generic 5.15.39
Uname: Linux 5.15.0-43-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu27.24
Architecture: amd64
CasperMD5CheckResult: skip
Date: Sat Aug 6 10:41:23 2022
InstallationDate: Installed on 2022-06-12 (55 days ago)
InstallationMedia: Kubuntu 20.04.4 LTS "Focal Fossa" - Release amd64 (20220223)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: grub2
UpgradeStatus: No upgrade log present (probably fresh install)

[Chris Guiver (guiverc)]

Thank you for taking the time to report this bug and helping to make Ubuntu better.

Bug reporting is mostly about finding & fixing problems thus preventing future users from hitting the same bug.

I suspect a Support site would be more appropriate, eg. https://answers.launchpad.net/ubuntu. You can also find help with your problem in the support forum of your local Ubuntu community http://loco.ubuntu.com/ or asking at https://askubuntu.com or https://ubuntuforums.org, or for more support options please look at https://discourse.ubuntu.com/t/community-support/709

Kubuntu & Lubuntu are both flavors, meaning they're built on the same Ubuntu base. If you didn't experience this with Lubuntu 20.04, but do with Kubuntu 20.04 where the base system is identical, I'd look for changes in the hardware. Especially if your system is using consumer grade components (with long warranties), they tend to retry many times rather than give errors resulting in warranty claims as only enterprise gear (with shorter warranties) have the higher performance warranties. Have you checked your drive health? (https://help.ubuntu.com/community/Smartmontools). You're using the HWE kernel stack with Kubuntu, which stack were you using with Lubuntu? was it GA or HWE? as both being flavors of Ubuntu, the ISO used to install dictates the default stack and thus switching your current Kubuntu 20.04 LTS from current HWE to GA (that possibly you used with Lubuntu) is an easy workaround. (fyi: your installation media was 20.04.4 thus HWE is default; what media did you install Lubuntu with? was it GA? (20.04 & 20.04.1) or HWE? (20.04.2 or later). Your system has already upgraded to 20.04.5 (5.15) kernel so did the issue occur with that updated kernel? does it occur if you select the installed 5.13 kernel? Support may help with some of these.

[js1 (sujiannming)]

Thanks for the response, which reminded me to try the Advanced Menu in Grub. It appears what's taking over 2 minutes is the loading of the ramdisk. The regular grub menu has no output once the selection has been made, so the screen goes blank for over 2 minutes. The advanced menu shows the kernel loading, then a few seconds later the ramdisk loading, then 2 minutes later kernel boot output.

[js1 (sujiannming)]

Yeah, the Advanced option entry has echo outputs, but the regular menu entry does not. Maybe the lack of echo outputs is the bug here, not that it takes 2 minutes to load the ramdisk. Although, loading the ramdisk for newer kernels seems to only take longer and longer.