[who] Removing dead connections?

[littlebigman]

Hello

Occasionnally, a remote host can have a problem while connected with SSH, and leave a dead connection:

# who
USER       TTY      IDLE      TIME           HOST
root       pts/0    00:00     Mar 10 23:35:1 somehost.acme.com
root       pts/1    00:14     Mar 11 00:25:2 somehost.acme.com
root       pts/2    ?         Mar 10 02:34:3 somehost.acme.com
root       pts/3    ?         Mar 10 18:56:4 somehost.acme.com
root       pts/4    ?         Feb 21 17:51:0 somehost.acme.com
root       pts/5    ?         Feb 26 00:31:2 somehost.acme.com

How can I remove those dead connections?

Thank you.

[anomie]

Identify the PIDs:
ps -ef | egrep 'PID|sshd'

then kill the PIDs associated with ttys.

[littlebigman]

Thanks, but dead connections aren't listed when I run the above, only the active connections:

# ps | egrep 'PID|sshd'
  PID  Uid        VSZ Stat Command
 1482 root       4412 S   /usr/sbin/sshd: root@pts/0
 1502 root       4472 S   /usr/sbin/sshd: root@pts/1
 1771 root       1780 S   /usr/sbin/sshd
 1790 root       1068 S   egrep PID|sshd

[anomie]

Use the -ef options with ps.

I'm not sure why grep'ing for sshd didn't show the old connections. Pipe all processes to less and see if you can locate the PIDs that way.

[littlebigman]

Sorry, but I forgot to mention it's a small Linux distro running of a Compact Flash card, and "ps" is from BusyBox, hence less features than the full-fledged version.

Dead SSH sessions aren't listed. I'll see if I can find how to remove them from "who".

Thanks.

[anomie]

In that case, you might plan for an appropriate time to restart sshd. I'd expect that to clean up what you're seeing.