Host logs prior the last boot ⚠️

[bcutter]

❓ How - To - Access - Host - Logs - From - Previous - Boot ❓

ha host logs -b-1 -n1000 does not work anymore (for months), only gives Logs only contain 1 boots.

So how shall we debug things if we can't access logs properly? I urgently need a solution for this (#3362 (comment)), tried almost everything. Not even ChatGPT is smart enough. Feels like some HA OS restrictions went a bit too far as this definitely was working in the past (!)

❓ How - To - Access - Host - Logs - From - Previous - Boot ❓

[sairon]

While it works on my main instance, I can reproduce it on another one, so there's definitely something wrong - I'll look into it.

As a workaround, if the logs aren't really lost (e.g. because of FS corruption), you can work it around by leaving out the -b-1 parameter and ignoring the logs from this boot, eventually increasing the -n parameter to get to the point where you need. If your instance recovered after the reboot, you can also use the frontend for logs which was greatly improved recently, and simply scroll up - it should continuously download older logs.

[bcutter]

1. Your frontend for logs link (/_my_redirect/logs?provider=host) only gives the last maybe 50 lines. Maybe a recent HA Core update is needed.
2. Increasing -n is not helpful as it still points to the single (current boot) file, that's why -b-X exists: to select older log files.
3. No idea why, but today (after another unexpected host reboot) the original ha host logs -b-1 -n1000 was working, providing log output from prior the current/last boot. Interestingly ha host logs -b-2 -n1000 gives Logs only contain 2 boots now.

Overall the log experience still is confusing and not consistent, thinks don't work reliably.

[sairon]

• Your frontend for logs link (/_my_redirect/logs?provider=host) only gives the last maybe 50 lines. Maybe a recent HA Core update is needed.

Of course, if you're running an old Core version, it may not be true. However, for several months already, the logs now have the "live" streaming feature plus "endless scrolling" implemented.

• Increasing -n is not helpful as it still points to the single (current boot) file, that's why -b-X exists: to select older log files.

Not really. The -b option exists to select a particular boot, but increasing the -n value always gives you more lines (if there are any), ignoring the boot boundaries. There was a bug that was fixed in Supervisor just recently (home-assistant/supervisor#5591) and that was probably the cause why you couldn't see the previous boot. By increasing the -n parameter, you'd eventually be able to see the logs from the previous boot in that case. However, there are still some cases when some of the failed boots wouldn't be shown, with large -n without the -b argument you can get to them. See:

# ha host logs -n1000000 -b-1 | wc -l
3685
# ha host logs -n1000000 -b0 | wc -l
4101
# ha host logs -n1000000 | wc -l
11523

• No idea why, but today (after another unexpected host reboot) the original ha host logs -b-1 -n1000 was working, providing log output from prior the current/last boot. Interestingly ha host logs -b-2 -n1000 gives Logs only contain 2 boots now.

What Supervisor version do you have? Can you access the host console and compare output of ha host logs boots and journalctl --list-boots?

[bcutter]

Ah great to know, thanks.

Running latest 2025.02.0 supervisor. I suspected something must have changed (there) as the current behavior definitely is an improvement since it broke somewhere in 2024.

ha host logs boots gives two lines with "-1" and "0" below.

journalctl does not exist - accessing via "Advanced SSH addon", no console access. Therefore no comparison possible.