[Samba] Restart Winbind

[Adam Nielsen]

> I wish I can put gdb, but when tdb files get corrupted, I cant login to
> the host even as a local user on console. Winbind seems to be locking
> the whole authentication stream.   I don't understand why even the local
> user cant login.

It's because normally (depending on /etc/nsswitch.conf) winbind will be
queried first before local files like /etc/passwd.  If you swap the
order you can make it check local auth files first.

Alternatively you should be able to get around that by either leaving a
console or SSH connection open to the server 24/7 until it breaks, or
perhaps using SSH with public keys, which should bypass the normal
authentication scheme.  Of course then even something like "ls" will
probably lock up, since it will query winbind to map UIDs back to
usernames...

> Thats the I'm working on a script to run w/ cron, so that when winbind
> consumes more than 40% cpu, I want to restart the cpu.

Short of tracking down the bug with gdb and fixing it, this is probably
the only alternative.

> I wanted to ask another question on the same subject. When I start the
> winbind using the init script, it forks 4 processes. The pid on
> /var/run/winbindd.pid is the parent process. So is that the pid I need
> to monitor to capture the true cpu utilization? 

I'm afraid I can't answer that, but it's possible that any of the
instances might lock up, so you would probably need to monitor all of
them.  Perhaps an easier option could be to time how long it takes to
run a command, and when winbind locks up and that command doesn't
complete, then you know winbind must be restarted.  (Even something like
"rm /tmp/heartbeat; ls; touch /tmp/heartbeat" would mean that if
/tmp/heartbeat disappeared for more than a few seconds you know
something is wrong.  "monit" probably has a test for this already and
would save cronjob scripting.

Cheers,
Adam.