[CentOS] Anyway to ensure SSH availability?

[Robert Heller]

At Wed, 29 Jun 2011 16:08:02 -0400 (EDT) CentOS mailing list <centos at centos.org> wrote:

> 
> >
> > Am 29.06.2011 um 21:50 schrieb Emmanuel Noobadmin:
> >
> >>
> >> Since I'm not the only person who face problems trying to remotely
> >> access a locked up server, surely somebody must had come up with a
> >> solution that didn't involve somebody/something hitting the power
> >> button?
> >
> >
> >
> > Yes, it's called "out of band management".
> > Have dial-in access to IPMI/iLO interfaces or just an APC remote
> > controlled power-switch to power-off the server.
> 
> Perhaps this suggestion is applicable:
> setup a cron job where the sshd server is restarted (once or several times
> per day, or per week, etc).
> 
> At one time, I had a server on an ISP that, with time, became woefully
> underpowered (the anti-spam/anti-virus program ate CPU power and RAM) to
> the point that occasionally, and with more frequency (once a week?) sshd
> would become unresponsive. This required that someone be at console to
> restart sshd; or if the problem was not understandable, reboot the box.
> 
> Having sshd restarted in cron worked until we got a new, soopa-doopa box.

If the problem is excessive load because Sendmail / Mimedefang / spamd /
etc. is too busy handling tons of mail/spam being dumped on your server, you
might want to look at these sendmail options:

ConnectionRateThrottle	(34.8.12)
MaxDaemonChildren	(34.8.35)

also 

QueueLA			(34.8.50)
RefuseLA		(34.8.54)

setting these can keep Sendmail (and Mimedefang, spamd,  etc.) from
overwhelming the system.

> 
> >
> > Rainer
> 
> Max
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>                                  

-- 
Robert Heller             -- 978-544-6933 / heller at deepsoft.com
Deepwoods Software        -- http://www.deepsoft.com/
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