[systemd-devel] --Reboot-- lines in journal

[Simon McVittie]

On Thu, 14 May 2020 at 16:12:49 +0300, Mantas Mikulėnas wrote:
> The "--Reboot--" line is simply shown every time the _BOOT_ID field changes
> between two entries -- even if it changes to a previously seen boot ID (which
> shouldn't happen normally, but *might* be caused by lack of a RTC?).

The Raspberry Pi doesn't have a real-time clock, so if the journal
is sorting log entries by their claimed timestamp rather than by the
order in which they were actually written, it's entirely possible that
different boots will get interleaved.

In a traditional syslogd-style log file where entries are written in
order, you'd see the wallclock time jump backwards at each reboot,
then jump forwards again when NTP/etc. resynchronizes.

    smcv