On Mi, 10 mar 21, 04:26:06, Richard Owlett wrote:
On 03/10/2021 03:45 AM, Andrei POPESCU wrote:
The boot process has three major stages.
1. POST: https://en.wikipedia.org/wiki/Power-on_self-test
2. Bootloader (grub, etc.)
3. Operating System (in this case Debian)
In which of the above stages does the boot hang?
In yesterday's case, it was definitely case 3.
In the case of getting a hang with blank screen I suspect it also was case
3, but I wasn't recording detailed symptoms the last time it happened.
I all cases I've heard the beep from POST.
Well, it should be pretty obvious if you are past the bootloader (grub)
stage or not ;)
Assuming the hang happens in the OS stage a first step would be to
remove 'quiet' from the boot command line. Both the kernel and systemd
(assuming the boot is progressing that far) should be significantly more
verbose then.
Consider this sequence of events.
1. PC and LinkZone powered off
2. Turn on PC
3. Debian boots normally
4. Turn on LinkZone
5. Browse a web site
6. Shut off PC power leaving LinkZone running on its battery
7. Wait
8. Turn on PC
9. Failure occurs
After a failed boot you could try to boot normally and check the output
of
journalctl -alb -1
('-1' means the logs from the previous boot)
Based on the timestamps you should be able to determine whether this is
the failed boot (assuming it got far enough to save the logs to
persistent storage) or the previous one.
This may not work unless you enable persistent storage for
systemd-journal (see /usr/share/doc/systemd/README.Debian).