sshd with zombie process on FreeBSD 10.0-STABLE - workaround

[John Baldwin]

On Wednesday, March 19, 2014 1:47:10 pm Marcelo Gondim wrote:
> Em 19/03/14 13:01, Kevin Oberman escreveu:
> > On Wed, Mar 19, 2014 at 6:00 AM, Marcelo Gondim 
<gondim at bsdinfo.com.br>wrote:
> >
> >> Hi all,
> >>
> >> While the solution does not appear, did the script below and put it in
> >> crontab to automatically delete zombie sshd processes.
> >>
> >> the_walking_dead.sh:
> >>
> >> #!/bin/sh
> >> kill -9 `ps afx|grep sshd|grep unknown|awk '{print $1}'`
> >>
> >>
> >> Put this in /etc/crontab:
> >>
> >> 00 1 * * *    root    the_walking_dead.sh
> >>
> >>
> > If 'kill -9' works, the process is not really a zombie. It simply still 
has
> > a socket open and is waiting for it to be closed before exiting.
> >
> > You might takes a look at network sockets with sockstat(1) and see if you
> > can get any indication of why these sockets are not being closed. It may 
be
> > that the issue is not sshd but some other issue in the OS leaving sockets
> > open.
> >
> Hi Kevin,
> 
> My ps -afx below:
> 
> [...]
> 42139  -  Is       0:00.01 sshd: unknown [priv] (sshd)
> 42140  -  Z        0:00.01 <defunct>
> 42141  -  IW       0:00.00 sshd: unknown [pam] (sshd)
> 58445  -  Is       0:00.01 sshd: unknown [priv] (sshd)
> 58446  -  Z        0:00.02 <defunct>
> 58447  -  IW       0:00.00 sshd: unknown [pam] (sshd)
> 65635  -  Is       0:00.01 sshd: vinicius [priv] (sshd)
> 65636  -  Z        0:00.01 <defunct>
> [...]
> 
> # sockstat | grep 42140
> #
> 
> # sockstat | grep 58446
> #
> 
> # sockstat | grep 65636
> #
> 
> No associated socket with zombie process.

Do a pstree.  I bet the zombies are children of the other processes that
are stuck on a socket as Kevin described.

-- 
John Baldwin