Find all possible logs to debug system failure

elusian

Hello

My laptop just locked up really badly. The screen kept updating, and I could move the mouse, but that's it. It refused any input, including force shutdown using the power button. Upowerd was taking a full CPU core. In the end I had to open the case and disconnect the battery. Not a fun time.

However, now it works and nothing appears to be broken.
I would still like to debug the failure, to understand what caused it and whether it can be avoided in the future.
journalctl -b -1 didn't help a lot, are there other logs I can check?

Thanks in advance

YuriTheHenrique

you can try installing gnome-logs it is a log viewer for systemd journal, it separates the logs by warnings, errors, hardware, and others. See if it can help you.

elusian

Thank you for the suggestion, good to know that journald logs can be inspected with a gui. Unfortunately, gnome-logs appears to be just a different way to print the results of journalctl -b -1, so it does not help in this case.
Whatever happened does not seem to have left traces in journald, that is why I was asking for other logs.
For example, can I recover the output of dmesg from previous boots? Or is it transitory?

brent

I'm surprised there was nothing valuable with the journalctlcommand. I believe dmesg has time-delimiters in the help/arguments sections. Wish I knew more log commands. You could also snoop around your var/tmp files but mine seem empty. Cool little dmesg tutorial here: https://www.howtogeek.com/449335/how-to-use-the-dmesg-command-on-linux/
--hope you figure it out

elusian

So, after looking a bit more: dmesg the command is not kept between boots, however its output is also available from journalctl. The reason why I wasn't finding it is that apparently if you want inspect the kernel log you need to use sudo.

Apparently there were some issues with ACPI and the laptop battery, the logs is full of messages like

Jul 30 19:38:49 me kernel: ACPI: \_SB_.PCI0.LPCB.BAT0: _BST evaluation failed: AE_TIME
Jul 30 19:38:49 me kernel: ACPI Error: AE_TIME, Returned by Handler for [EmbeddedControl] (20210331/evregion-281)
Jul 30 19:38:49 me kernel: ACPI Error: Timeout from EC hardware or EC device driver (20210331/evregion-291)
Jul 30 19:38:49 me kernel: ACPI Error: Aborting method \_SB.PCI0.LPCB.BAT0._BST due to previous error (AE_TIME) (20210331/psparse-529)