Re: sysadmin qualifications (Re: apt-get vs. aptitude)

[Jerry Stuckle <jstuckle@attglobal.net>]

On 10/15/2013 7:40 PM, berenger.morel@neutralite.org wrote:
> Le 15.10.2013 18:28, Jerry Stuckle a écrit :
> > Why?  Do you know how a TV signal is encoded at the station?  How it
> > is modulated onto the carrier?  The operation of the RF and IF strips
> > in your TV?  The frequencies of the local oscillator(s) being used?
> > How the RF signal is demodulated?  How the video and audio are
> > decoded?  How the video is displayed on the screen?  How the audio
> > ends up at the speakers?
> >
> > Or do you just turn it on and watch your favorite show?
>
> If I am a simple user, I can live without knowing nothing, yes. But I
> can hardly consider programmers as simple users... And, no, I do not
> know everything about the TV, but I know some stuff related to it's
> general working, like, for example, that to have an image I need to capt
> a radio signal from a satellite (ok, it's not the only way, I know),
> which is turned into an electrical analog signal, itself converted to a
> numerical one, which is finally interpreted to generate and image and
> sound.
>
> And this small knowledge allows me to understand why and how I need to
> move the parabolic antenna, so that I am able to simply use my TV then,
> without the need of giving a lot of money to someone who will need lot
> of time to fix it for me (lot of time, because I'll have to wait him to
> go at my home). So, it makes me able to use my TV  quicker, and to fix
> minor problems if, by example, a strong wind moved the antenna.

Ah, but you are more than a "simple user".  You can change channels. You 
can increase/decrease the volume.  If you have a DVR, you should be able 
to record and play back.

> > > By example, in my last job, I was able to speak with the sysadmins,
> > > because I have knowledge about stuff that I do not need to know: linux,
> > > networking, firewalls (hardware and software), active directory, and
> > > that kind of stuff that programmers do not need. But it always helps to
> > > have knowledge you do not need, and if I did not liked that idea when I
> > > was younger, I now love it.
> > > It is named general culture I think (if that translation from the French
> > > expression is correct).
> >
> > None of which has anything to do with the OSI layers or programming.
> > They are all sysadmin functions.
>
> Yes, I was speaking about the interest of being able to understand
> something that you do not really need to know.
>
> > It doesn't hurt to have knowledge you don't need now.  But this world
> > is way too complex to know everything about everything.
>
> I agree. But to be able to communicate with someone which knows what you
> ignore, you will need common bases to explain what you need. People with
> very very good knowledge of their domain, but no knowledge in others'
> domains will need someone able to act as an translator. I have heard lot
> of stories of very very good computer scientist who mades very very good
> programs. But the programs were not used, because they were not adequate
> to user's needs.
>
> That's why people have to know basics of other's sciences, and why
> general culture is important, for me. But maybe I think that because it
> is the way teaching is made in France, from centuries. I know that the
> biological knowledge (very basic one, of course, stuff about cellular
> atomic kernels, DNA, and alike.) I have acquired at a time is not very
> useful. But it made me able to discuss with my neighbor when I was in
> higher studies, and also inspired me some ideas for algorithms.

Which is also why Universities require about 3/4 of the course hours be 
outside of your major.

> > Just like I
> > don't program in assembler (for Intel or Motorola MPUs or IBM
> > mainframes), although I could do any of them still.
>
> I do not do it either. But by being able to do so, I can understood why
> some instructions will slow down programs more than others. Of course,
> early optimization is root of evil, but I know that if I have to
> divide/multiply integers by a power of 2, I can use the << and >>
> operators. It also helps me when I need to debug programs, even if I do
> not have the source code.
>
> > Pointers have nothing to do with assembler.
>
> Pointers are memory addresses, which are very important in asm. So, yes,
> knowing asm helped me a lot to understand C pointers. I understood them
> without any problem, unlike my classmates. And those guys were, as me,
> coming from electronic studies, so they were supposed to know basics
> about processors.

Yes, my C/C++ students sometimes had initial problems with pointers, but 
some real-world (non-programming) examples got the point across quickly 
and they grew to at least accept them, if they didn't like them. :)

> > C is not the only
> > language with pointers
>
> Of course. They all need to use them if they offer dynamic stuff, but
> they try to hide them. Is it the good solution or not? I do not know,
> but if yes, I wonder why most games are written in C or C++? I think
> that guys who write them knows what is memory, and how it works. I hope
> for them at least.

C was never meant to be an applications language - K&R designed it for 
creating OS's (specifically Unix).  But because of that design, a good 
programmer can write code that is smaller and faster than with other 
languages (except assembler, of course).  A bigger advantage is the code 
is machine-independent.  For instance, I can write an application in C 
to run on Debian on X86 - but that same application, by being 
recompiled, will also run on an ARM device.

> > But it doesn't require knowledge of underlying memory
> > access to use pointers.
> > I've taught many C and C++ classes over the
> > years (I used to do corporate programmer training), and never once did
> > we get into how memory works.
>
> I wonder how you taught how to use them, so. Just saying that they are
> variables which indicates where in memory are located other variables?
> And people just accept that?

Nope, real-world examples unrelated to programming.

> > Those who never programmed in languages
> > with pointers, i.e. COBOL, had a little trouble getting used to them,
>
> Yes. It is what I said. General culture helps to learn new things
> faster. Not needed, but helps.

Actually, in this case, new programmers pick it up faster than 
experienced programmers.  The same is basically true with OO programming 
techniques - the longer someone has been using functional programming, 
the harder it is for him/her to make the jump.

> > > Plus, here, we are not discussing about programming, but about
> > > networking, so I think minimal knowledge of network stuff and some
> > > electric basis can be useful ;)
> >
> > Not really.  When you're troubleshooting network problems in low
> > level code, it is important.  Otherwise it's no more important than
> > knowing how everything in your TV works.
>
> So, you are able to do right choices when you buy hardware without
> knowing how it works? Interesting, but I doubt it.
> By right choices, I do not mean "buying the one with the highest perfs",
> I mean "buying the one which fit your exact needs".

Buying hardware is different from programming.  There are millions of 
programmers in the world who never bought a bit of the hardware they are 
working on.

> If you have no understanding about what the hell is a parasite, you will
> always buy armored cables, even if you only need a small piece of cable
> far from any parasite generator. Waste of money.

Do you mean a parasite generator, or a parasitic generator?  Either way 
- it isn't the programmer who buys the cables.  It is the engineer.

> But, in a sense, you are right: it is only useful to troubleshoot
> problems, and creating stuff, installing stuff, gives problems. By doing
> nothing by yourself, you will still have problems: financial ones, this
> time.

--
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Jerry Stuckle
JDS Computer Training Corp.
jstucklex@attglobal.net
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