Reboot from the command line (stuck processes)

Question

I started a remote reboot of my machine but a couple of stuck processes are hanging the reboot.

• login with SSH is still possible
• sudo reboot or sudo shutdown -r hang

• two processes are trying to exit

  USER             PID  PPID  PGID   SESS JOBC STAT   TT       TIME COMMAND
  root              43     1    43      0    0 ?Es    ??    0:00.00 (mds)
  corti            407   376   407      0    1 ?E     ??    0:00.00 (talagent)
  

• I did not manage to kill them (i.e., sudo kill -9 43 or sudo kill -9 407 have not effect)

• A remote desktop session is no more possible (last screen that I got was a gray screen with the wheel while shutting down)
• Trying to reboot without flushing the caches does also hang (any combination of -n and -q)

Any other things I could try other than going home and physically reboot the machine?

Answer 1

If you can't kill something with -9, and sudo reboot doesn't work, you're pretty much out of options. The process is deadlocked in a manner that has prevented the OS from shutting down.

Have you closed all other Windowed applications? talagent is apparently the process that manages Resume, your guess is as good as mine in determining why it's deadlocked; Errors communicating with a process it was trying to save before closing, disk errors, etc. Since it's attempting to exit, it's unlikely that anything else (forcing system sleep, closing the process it was waiting on) will cause this process to work out it's lock.

The power button is necessary at this point.

Answer 2

sudo reboot -nq

-n file system cache not flushed

-q restarted quickly and ungracefully, and only the flushing of the file system cache is performed (if the -n option is not specified)

Notes:

• Both options should probably not be used: first try without, then -q, then -qn.
• Wait 5-15 minutes.
• Don't expect a shutdown acknowledgement.
• A "Broken pipe" disconnect message appears later then with regular reboots.

This is a uncontrolled shutdown and the only worse thing for data / filesystem is holding the power button, but if you've already quit all the apps that can quit and waited 10 minutes, it's not likely a clean landing can happen at this point.