Unwanted System shutdown after SSH logout

Question

Hi, I am new to the forum and I can'r resolve by myself this problem:
I have a small server where I connect via SSH from internet.
Everything is working ok but I noticed that after the system update via pacman -Syu I have this strange shutdown whenever I logoff from the SSH session.
the system is Linux srv 3.18.6-1-ARCH #1 SMP PREEMPT Sat Feb 7 08:59:29 CET 2015 i686 GNU/Linux
I looked at the log and the system appears to receive a shutdown command.
Here is the last log extract:
mar 05 17:00:35 srv sshd[368]: Received disconnect from xxx.xxx.xxx.xxx: disconnected by user
mar 05 17:00:35 srv sshd[363]: pam_unix(sshd:session): session closed for user xxx
mar 05 17:00:35 srv systemd-logind[201]: Removed session c1.
mar 05 17:00:35 srv systemd[365]: Stopping Default.
mar 05 17:00:35 srv systemd[365]: Stopped target Default.
mar 05 17:00:35 srv systemd[365]: Starting Shutdown.
mar 05 17:00:35 srv systemd[365]: Reached target Shutdown.
mar 05 17:00:35 srv systemd[365]: Starting Exit the Session...
mar 05 17:00:35 srv systemd[365]: Stopping Basic System.
mar 05 17:00:35 srv systemd[365]: Stopped target Basic System.
mar 05 17:00:35 srv systemd[365]: Stopping Paths.
mar 05 17:00:35 srv systemd[365]: Stopped target Paths.
mar 05 17:00:35 srv systemd[365]: Stopping Sockets.
mar 05 17:00:35 srv systemd[365]: Stopped target Sockets.
mar 05 17:00:35 srv systemd[365]: Stopping Timers.
mar 05 17:00:35 srv systemd[365]: Stopped target Timers.
mar 05 17:00:35 srv systemd[365]: Received SIGRTMIN+24 from PID 1119 (kill).
mar 05 17:00:35 srv systemd[366]: pam_unix(systemd-user:session): session closed for user xxx
The system is a server only with remote console, no keyboard, no monitor.
Any idea where to look for to solve these unexpected shutdowns?
Thank you.
Giorgio

Answer 1

Friend, I feel for you. I have the same problem on two PPC machines. I have watched posts about this problem for about a year now, and I have yet to see anyone come close to a fix.
I'm going to tell you how we keep it from happening 97% of the time (on both our machines). It's really weird, but it works. When we're going to shut down, we open a few folders and let the machine calculate the sizes of the items inside. We use the Applications folder and the Utilities folder for this. Once the machine has shown the sizes of the items in the window, we close the window. Then, from the Apple Menu, we choose Shut Down (or Restart, if that's what we're doing). The dialogue window appears, asking to confirm that is what we want to do. Now, WAIT as it counts down. Click "OK" when the countdown hits 55 seconds remaining. I know it sounds goofy, but believe me, it works. If we do not follow this routine, the shutdown or restart will fail and we have to force quit the machine.
Now, we've been doing this for a long time - probably about a year. Since we started having to follow this silliness, we have installed a second hard drive in the desktop machine and also now use a portable FW HD with my laptop. On the laptop, I always eject the external HD before shutdown or restart. On the desktop machine, we simply open at least one big folder (usually Applications on a clone backup partition, and on the other partition just some big folder), let it calculate the sizes of the enclosed items, then close those folders. Following these actions, we use the previously described procedure.
Try it and let me know here if it works for you.
I know it sounds totally insane, but it works. It's a pain to do it every time, but it beats a forced shutdown and the chance of data corruption. I've given up on a solution; we'll probably replace these machines before there's a fix - judging from the lack of success other have with this problem.