Has anyone here noticed weird behavior where userland on can be alive and well
during quite late shutdown phases?
First, I noticed this report on FreeBSD forums.
Initially, I didn't find it believable, but the poster provided quite strong
evidence and details.
https://forums.freebsd.org/threads/zombie-kernel-reporting-its-own-crash-via-network.95217/
Then recently, I first hand experienced a similar thing during a normal reboot
of a system. Here is console output from an ssh session connected to a host
name 'ryth':
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
29759/usr/home/avg
pts/1:[0]:ryth#18:28>poweroff ; exit
Shutdown NOW!
poweroff: [pid 14930]
*** FINAL System shutdown message from root@ryth ***
System going down IMMEDIATELY
System shutdown time has arrived
[root shell exited, but user shell is still active on ryth]
28923/usr/home/avg
pts/1:[0]:ryth-18:28>tail -30 /var/log/messages
[snip]
Nov 3 18:28:25 ryth shutdown[14930]: power-down by root:
Nov 3 18:28:25 ryth ntpd[2088]: ntpd exiting on signal 15 (Terminated)
Nov 3 18:28:25 ryth upsmon[1989]: upsmon parent: read
Nov 3 18:28:25 ryth kernel: .
Nov 3 18:28:26 ryth kernel: , 1739.
Nov 3 18:28:26 ryth kernel: Waiting (max 60 seconds) for system process `vnlru'
to stop... done
Nov 3 18:28:26 ryth kernel: Waiting (max 60 seconds) for system process
`syncer' to stop...
Nov 3 18:28:26 ryth kernel: Syncing disks, vnodes remaining... 0
Nov 3 18:28:27 ryth kernel: 0
28924/usr/home/avg
pts/1:[0]:ryth-18:28>
[finally ssh (slogin) gets disconnected]
Connection to 192.168.0.77 closed by remote host.
Connection to 192.168.0.77 closed.
zsh: exit 255 slogin ryth
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
It was a weird feeling seeing "Syncing disks, vnodes remaining..." in messages.
--
Andriy Gapon
