Hадеюсь, автор меня простит, что я заслал эту статью в русскоязычные
конференции. Мне понравились его рассуждения, хотя ничего нового он
и не сказал. Простенько и со вкусом.
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Howdy,
Shoen wrote in message <352C6318.A6B0AD9F@swbell.net>...
>Hi
>
> I have two questions. First off I have a friend who is wondering
>why I want to learn Unix and since I'm brand new to it I can't really
>give any examples. Can you guys provide me with examples I can give?
>What are some things that make Unix a better OS than Win 95 NT or DOS?
>This will also give ME a better idea of what I can expect to be able to
>do as I get better at this.
Oy, loaded question! I could give you the religious answer that anything MS
does is bloatware and inferior, but that's not wholly true. It's better to
clasify OS's and their purposes and uses.
Win95 is a personal operating system. It is by far the most popular OS in
existence, largely because of Microsoft marketting and relative ease of
developement (for applications programmers). It features many conveniences
but sacrifices stability, especially in complex systems or under heavy
loads. This is why most Win95 systems need to be rebooted at least once a
week if not once a day. It's funny that the most stable Win95 system I
manage is a 386DX-40 with 20MB RAM; it's slow, but it rarely if ever crashes
or locks up, even though I'm running IE4.01 with active desktop turned on
(and I never turn it off).
WinNT comes in various flavors (Workstation, Server, Enterprise Server) but
is the same OS under the hood. It sports a number of compromises on video
and memory management (for speed's sake) but makes a good file and
application server (to a point). Its network services, however, are not yet
very secure. Securing an NT system requires quite a few extra steps, and
some things cannot be protected (from what I hear). One of MS' weaknesses
in fixing security problems with NT has been that they fix the problem
specific to an exploit (such as might be published on rootshell.com) rather
than the broader problem demonstrated by the exploit. This reduces
confidence in MS' fixes to problems. Another NT weakness is the
aforementioned memory management. Most NT systems have to be beefed up by
as much as 50% (or more) in RAM to function at the same level as a like Unix
system.
Many companies are happy with NT. Many companies have moved from Unix to NT
only to move back, unable to tolerate frequent crashes (NT's average is
reported as every two weeks, vs. Unix being one _year_, though mileage
varies) and network downtime.
One BIG weakness in NT is the registry (also used in Win95/Win98). If the
registry gets damaged or cracked, then the system usually needs to be
re-installed from the ground up. This dependency on a single, central
database is considered one of the biggest system and security risks in NT.
Unix is a scaleable OS (like NT, only more so at this time), running from
workstations up to mainframes. The underlying OS families (AT&T's System V
versus Berkeley Software Design (BSD)) mostly use the same commands and OS
structures. Once you know Unix at one level, you more-or-less know Unix at
any level, so the "different flavors" issue is not that important. There
are some adjustments you must learn if you are an expert on one Unix (like
Unixware) and move to another Unix (like Solaris/SunOS), but they are
relatively minor. If you know how to navigate and administer SCO Unix on a
Pentium 166 ($600), then you're over halfway to administering SunOS on an
UltraSPARC server ($40,000 and up?). (This is not to say that SCO
Unix/OSR5/UnixWare doesn't scale up to budget-buster machines. We use SCO
Unix/OSR5 on Compaq servers and are Very Happy with the power they deliver.)
Unix is also a very well established OS family, now running up towards 30
years! It's not old or out of date; Unix developers keep improving their
OS's every month. The nice thing is that Unix has worked out most of the
basic security bugs. "New" holes tend to be old holes that were re-openned
and are readily closed. Memory management is very efficient, and the
various filesystem types give scaleable performance for different needs.
"But Unix is a character-based OS and Windows is graphically-based and,
therefore, better." I hear that a lot. Let's blow that one out of the
water right now:
Operating systems are neither character-based or graphically-based. OS's
are a collection of programs and drivers that turn a piece of expensive,
dead iron into a working computer system, capable of processing and routing
information. The OS doesn't know squat about characters or graphics; it
knows how to run the machine (the hard drives, the keyboard, the monitor,
the comm and network ports, etc.). The developer then adds tools by which
to configure, manage and troubleshoot the OS. Those tools depend on a user
interface, either character or graphical or both. Any tool can be developed
on either side or both sides with equal effectiveness. What's important is
the usefullness of the tool itself.
Microsoft chooses to develope its OS tools only for the Windows graphical
environment. The limited character-based tools are a mere ghost of the
graphical tools. Those tools are not necessarily easier to run in a
graphical interface, that's just how Microsoft chooses to write them.
They've committed themselves to the Windows GUI/API on all their platforms.
SCO, just as an example, with OpenServer5, went to admin tools written in
TCL (Tool Command Language), which is an interpretive lanquage. SCO writes
a script that runs under a TCL runtime engine (a program that reads the
script and draws the screen, with menus, windows, buttons, scroll-bars,
etc.). Theres a TCL runtime engine for character-based interfaces and one
for X-Windows (even for MS Windows and MacOS, but that's another thing
altogether). Either runtime reads the same utility script. The result is
that the utilites look the same in the character side and the graphical
side, save that the graphical side may also have clickable buttons that are
ignored by the character-runtime. This is an example of utilities with
equal functionality in graphical and character modes.
Stepping down from admin tools, we come to actual program tools (usually
called by the admin tools). These are programs that do not have an
interface; they just take parameters and perform actions. These
tools/programs create users, add hard disks, manage files, setup network
connection, and lots of other things. An experienced admin will know a lot
of the tools and can quickly perform any number of tasks from a command
line, far more quickly than could be done by moving a mouse through a bunch
of menus and typing the occassional bit of input. NT is missing all these
features. You _have to be at the console of the computer_ to do most of the
basic admin chores on an NT system.
You ever see those AT&T video-telephones at the airport? Some of them have
keyboards. Funny, isn't it? Why would they have keyboards? It's a bit
arcane, isn't it? Well, I could, from one of those phones say, in Dallas,
dial into one of my systems, say in Bend, Oregon, using one of those phones,
and add users, kill programs, reconfigure hard drives (with the right setup,
even the root filesystem (modem on com1, booted from floppy, using
bootstring to move console to com1, with modem hard-set to auto-answer,
baud-rates set correctly)), and even reboot the system, all with the basic
Unix OS as it comes out of the box! With NT I would have to have a laptop
at a minimum with some remote-control software (local and on the NT system)
that lets me run the system console on the NT system and then SLOWLY drag my
mouse around to run the tasks in the graphical interface. On the Unix
systems, when I dial in, I've got my own screen and whoever is using the
console at the time doesn't even know I'm on the system. Such things make
my job MUCH easier.
So, is Unix better? Yes and no. It depends on what you're doing and what
you want done. Is Unix more expensive? Yes and no. A 5-user NT server is
less than a 5-user SCO Unix, but I would have to buy a LOT of additional
stuff for the NT system to get the same functionality as the Unix system.
For example: email (buy MS Exchange Server (a groupware package) or a 3rd
party mail server versus email server included with the Unix system), or
communications (buy remote access software for NT versus setting up modems
on the Unix system with included utilities). Unix also comes with loads of
basic tools that can be scripted together in a shell script (not batch-files
on steroids, but a real interpreted programming language) to perform complex
tasks or generate reports.
Unix admins, good ones at least, make good money. NT admins are catching up
to a point. Learn to administer both in a mixed environment and you are on
your way to a well paid job. Unix admins are highly in demand.
Check out www.ora.com (O'Reilly) for some good books on Unix and Unix admin,
like "Essential System Administration" and "Unix in a Nutshell".
"What about Linux?" More religious stuff? No, another good OS on it's way
up. Why is it good? It's modeled on Unix, for a start. Read and learn
about Linux; you'll see a lot more of it in the near future.
The real thing to remember is: don't buy an OS, buy a solution. Find the
software that best serves the purpose, find the OS it runs on best, and the
hardware to support it.
> My second question is this. I have UW 2.1.2 . I'm trying to set up
>my modem but it's jumpered to com3 because it works better that way in
>windows 95. What is the Unix equivalent to com 3? It's not one of the
>choices in my modem setup and when I put com3 in the "other" field it
>says I need to use the proper device name. (whatever that is) . I tried
>to look it up in the manual but just like every other manual I ever
>read, it has the answers to every other question but the one I need.
>Has anyone else out there gone through this one.
I've never configured anything in UW, so I don't know where to start. I
know com3 is not configured by default; you have to use one of the admin
tools to do that. In SCO Unix I would use the command 'mkdev', but you most
likely have a slightly different command in UW. I would say start with the
Intro man page ('man Intro'), which should include a fairly complete list of
commands, including short descriptions. You would follow that by reading
the man pages for the commands that look best. The result will be an entry
in the /dev directory that represents com3 (not likely to be /dev/com3, by
the way).
SCO should have some fairly complete online docs for UW. If you're using
the X-Windows interface, start with Help or an icon for manuals or
documentation. Read. Get a couple of good, basic "here's Unix" books.
Believe it or not I started with "Unix for Dummies" back in 1993 and rapidly
progressed through a number of increasingly complex books. I presently
administer 15 SCO Unix/OSR5 systems, a few Macs, and a bunch of Win95
systems. I'm also helping with some SunOS 4 and 5 systems (and catching up
on the differences as fast as I can), plus I have a couple of Linux systems
running in the office. Read, tinker, learn, ask questions, read, be
careful, leave yourself a way back, read, ask questions.
>I'd also like to thank you people in this group. I've posted questions
>before and always gotten mature and helpful answers. No one has ever
>tried to make me feel stupid for not knowing something. It says a lot
>about the caliber off people in this group.
We're not zealots, just people doing our jobs with the best tools we can
use, our brains.
Scot
-- Scot Harkins (KA5KDU) | Systems Administrator, Thurman Ind, Bothell, WA North Bend, WA | Native Texan. Proud daddy and husband! scoth@wolfenet.com | SCA: Ld. Scot MacFin, Barony of Madrone, An Tir scoth@scn.org/msn.com | URL <http://www.wolfenet.com/~scoth>
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