I just installed updates, rebooted (cleanly, as far as I know),
and when the system came back, 1 CPU was pegged at 100% running
rsyslogd. It stayed that way for a minute or two, then went
back to normal. In /var/log/messages, I found this:
Sep 29 07:29:31 tomh rsyslogd-2177: imjournal: begin to drop messages due to
rate-limiting
That was the very first message following the boot, most of
the junk that usually shows up on a boot was missing.
The last message prior to that was time stamped Sep 21, so I don't
know where all the messages between the 21st and 29th might
have gone - perhaps someone was saving them up till the next
reboot and that was why the cpu was pegged?