I start 2 vnc sessions at boot time using cron, e.g.

	% crontab -l
	@reboot ssh-agent vncserver :42
	@reboot sleep 3; ssh-agent vncserver :43

UID != 0

Problem: The first ssh-agent gets killed. Suspect is the
second agent. The first vnc session has no connection to
an ssh-agent. Besides that, both are fine. SSH_AGENT_PID
and SSH_AUTH_SOCK are defined in both sessions, but of
course they do not match.

If I login on the console, then libpam-ssh gives me yet
another new ssh-agent, and the 2nd vncserver agent is
pushing up the daisies, too.

The man page doesn't say "only one ssh-agent per user".
From my understanding they should not interfere with each
other. Esp. SSH_AUTH_SOCK is based on the agent's PID to
make sure that several agents can run in parallel.

Further the agents should not die while their children
are still running.


Regards
Harri

2015-10-07 09:30:12 Harald Dunkel:

Please do an strace on the ssh-agent to find out why it dies:

@reboot strace -ttTffo st ssh-agent vncserver :42
@reboot sleep 3; strace -ttTffo st ssh-agent vncserver :43

Keep the sessions short or the output files get really large; perhaps you can
just wait until the process dies and then kill all of the remaining processes.


Grüße
Timo

Attached.

Seems my observation was not correct: Both ssh-agents die
after some time, independent from each other. Apparently
ssh-agent doesn't manage a process group, but just a single
child. If it exits, then ssh-agent terminates, too, ignoring
the grand children (started by the vncserver wrapper script,
for example).


Regards
Harri