99.9% uptime

[Robert Sandilands]

On Fri, 15 Oct 1999, Peter J. Holzer wrote:

I've had the recent experience of converting from NT to Samba 2.0.5a +
Redhat 5.2. My NT server I had to reboot once a week due to the fact that
either my HP backup device stopped working or that it became so confused
with the number of times our clients crashed that we had problems
accessing files/logging in. With Samba now running for 6 months, I have
yet to reboot my server for any other reason than my stupidity. I have to
agree with the effects of 99.9 %. What it really is all about is that the
Samba server is 1/2 the maintenance of the NT machine, because I have
less to do to keep a running system. Although it leaves me more time
to do stupid things :-)

> On 1999-10-15 22:46:22 +1000, Hall, Ken (ECSS) wrote:
> > I was reading a comment this morning about something Microsoft had
> > published to the effect that there were vendors guaranteeing 99.9%
> > uptime for NT. The guy who wrote the reply did the math for what that
> > means, and the results are very interesting.
> >
> > Quote below:
> >
> >>  OK, now what does a 99.9% uptime guarantee mean? Well, it means
> >> that at bottom, a guarantee that the machine will not be down for
> >> more than one one-thousandth of the time. If we assume that we have
> >> a stable system, ie., one where the system is not taken down for
> >> software upgrades, etc.,
> 
> I think this is a big assumption. Apart from the occasional crash in the
> evening which wasn't noticed until next morning, all our long downtimes
> in the last few years were caused by software or hardware upgrades (and
> with the large HP-UX servers, were are generally in the 99.9% range).
> Basically, I think a guarantuee of 99.9% uptime is a guarantuee that
> you won't have to upgrade/reinstall more than once per year.
> 
> You will also have to consider that users generelly aren't interested in
> a running OS but in some service. So if I have to shut down samba for
> half an hour to enlarge some file system, that's half an hour of down
> time as far as my users are concerned. 
> 
> 	hp
> 
> -- 
>    _  | Peter J. Holzer             | Nobody should ever have to be
> |_|_) | Sysadmin WSR / Obmann LUGA  | ashamed if they have a secret love
> | |   | hjp at wsr.ac.at               | for writing computer programs that
> __/   | http://wsrx.wsr.ac.at/~hjp/ | actually work.  -- Donald E. Knuth
> 

_________________________________________________________________________
There is nobody to represent but myself.
-------------------------------------------------------------------------
        Robert Sandilands - sadness, anger, disappointment
 Tel: +27-12-349-2670, Fax: +27-12-349-2677, Email: robert at vps.co.za
-------------------------------------------------------------------------