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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
<html>
<head>
<title>The Answer Guy Issue 21</title>
</head>
<BODY BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#0020F0"
ALINK="#FF0000">
<!--endcut ========================================================= -->
<H4>&quot;Linux Gazette...<I>making Linux just a little more fun!</I>&quot;
</H4>
<P> <hr> <P>
<!-- =============================================================== -->
<center>
<H1><A NAME="answer">
<img src="../gx/ans.gif" alt="" border=0 align=middle>
The Answer Guy
<img src="../gx/ans.gif" alt="" border=0 align=middle>
</A></H1> <BR>
<H4>By James T. Dennis,
<a href="mailto:jimd@starshine.org">jimd@starshine.org</a><BR>
Starshine Technical Services, <A HREF="http://www.starshine.org/">
http://www.starshine.org/</A> </H4>
</center>
<p><hr><p>
<H3>Contents:</H3>
<ul>
<li><a HREF="./lg_answer21.html#control">Linux Control Panel</a>
<li><a HREF="./lg_answer21.html#command">Linux Command Line Arguments</a>
<li><a HREF="./lg_answer21.html#crash">More Random Crashes</a>
<li><a HREF="./lg_answer21.html#disk">More on Disk Defrag</a>
<li><a HREF="./lg_answer21.html#xwind">X-Windows is Crashing</a>
<li><a HREF="./lg_answer21.html#lynx">Lunx and Frames</a>
<li><a HREF="./lg_answer21.html#ftpd">More on ftpd</a>
<li><a HREF="./lg_answer21.html#dns">DNS Problem</a>
<li><a HREF="./lg_answer21.html#sendmail">Sendmail</a>
<li><a HREF="./lg_answer21.html#server">Linux PPP Server</a>
<li><a HREF="./lg_answer21.html#emulator">Linux/Unix Emulator</a>
<li><a HREF="./lg_answer21.html#lilo">LILO Concerns</a>
<li><a HREF="./lg_answer21.html#crypt">Crypt</a>
<li><a HREF="./lg_answer21.html#apache">Apache 1.2.1</a>
<li><a HREF="./lg_answer21.html#internet">PPP and Internet MCI</a>
<li><a HREF="./lg_answer21.html#auto">Enabling Automounter on a Linux
Notebook</a>
<li><a HREF="./lg_answer21.html#locks">XLocks Monitor</a>
<li><a HREF="./lg_answer21.html#pop">Pop3d That Doesn't Use /etc/passwd</a>
<li><a HREF="./lg_answer21.html#notebook">Configuration of Two Ethernet
Cards</a>
<li><a HREF="./lg_answer21.html#console">Attaching a Colsole to a PC</a>
</ul>
<p><hr><p>
<!--================================================================-->
<a name="control"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
Linux Control Panel
</h3>
<P> <B>
To: <a href="mailto:ggonzale@ix.netcom.com">ggonzale@ix.netcom.com</a>
</B><p><B>I have recently installed RedHat Linux ver 4.2 on my pc . My problem is
that I cannot get the control-panel to work when I run startx or XDM .
The panel comes up but I am unable to activiate any buttons in
control-panel . I don't know what I did wrong or what to check ! Please
help...
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
Are you running it as root?
Are there any interesting error messages in /var/log/messages?
Are there any interesteing error messages back on the text
console from which you ran "startx" (you can switch out
of XFree86 with {Ctrl}+{Alt}+{Fx} -- where {Fx} is the
function key that corresponds to any of you other virtual
consoles). Are you sure you installed the Python and
related libraries (last I heard all of the Red Hat GUI
control panel stuff is written in Python).
<p> As I've said several times -- I'm not a Red Hat specialist
(although that is what I'm running here at the moment) and
I barely use X (since I vastly prefer old fashion text mode).
<p> Have they ever gotten a support line running that can
answer questions that are specific to their code? (Hey!
I wouldn't even object to a paid support line -- if it
was good).
<P><B><img align=bottom alt=" " src="../gx/ques.gif">
Thank you for responding to my question I will look into the areas
you suggested . However I have one other question that is how would I
activate my modem from a Linux command line? I thought I needed the
xwindow to do that in the first place.
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
One of the virtues of Unix is that you don't need X Windows
to do anything except run X applications -- there are other
ways to access graphics (SVGALib, MGR) use your mouse (GPM)
do cut and paste (GPM/select, 'screen'), provide task/session
switching (virtual consoles, and 'screen'), do screen management
('splitvt', emacs) etc.
<p> In answer to your question regarding modems:
There are a number of programs that are included with the
typical Linux distribution that may use your modem:
<p>pppd is the PPP daemon -- it usually uses the 'chat'
command to talk to the modem.
<p>minicom is a vaguely Telix like ncurses terminal emulation
package (Telix is a popular shareware MS-DOS program).
It provides a fullscreen, color interface.
<p>'cu' is a "call utility" usually associated with UUCP.
It uses the UUCP configuration files for information
about your modem -- if you have those configured. It's
a very limited communications package -- that's only
virtue is that it is small.
<p>UUCP is a suite of programs -- of which the uucico
program actually talks to the modem. You almost certainly
are not planning on using this. However UUCP was (and
still is) used as a mail, file, and netnews transport
protocol for years before TCP/IP existed. I still use it
for my mail.
<p>C-Kermit is a communications package from Columbia
University. You can fetch it freely -- but it can't be
included with Linux (or other) CD-ROM collections of
software due to it's licensing model. If you decide you
like it you should buy a copy of the C-Kermit book by
Frank da Cruz (the program's principal architect and
head of the project since it's foundation).
<p> C-Kermit is also a scripting language and can be used
as a telnet or rlogin client, and Kermit is a file
transfer protocol which can be used by C-Kermit over
any communications channel that it can establish. I
wrote an article for SysAdmin Magazine on the subject
just a couple of months ago.
<p> There are other program that access your modem if
you want to use them, There's a SLIP package which
usually controls the modem via 'dip' -- there's
a variety of different "getty" implementations which
"Get a tty" (terminal) so that you can log in from a
terminal, or another system running a terminal package.
<p> I use mgetty which not only allows incoming dial-up
data connections but adds support for FAX and even
voice/DTMF with some modems. That package also includes
"sendfax" -- a program for outgoing faxes. efax is
another package for support FAXes under Linux.
<p> Judging from your earlier question regarding the Red Hat
Control Panel I suspect that you're just interested in
configuring your system for PPP access to your Internet
service provider (ISP). There is a script floating around (on
http://sunsite.unc.edu somewhere) called 'pppsetup'. I think
this will allow you to setup your PPP configuration from a
text console (I used plain old 'vi' and made my own
configuration files -- so I've never used this -- though I've
seen it recommended many times).
<p> There are several HOW-TO's on configuring PPP (and SLIP) which
can be found at <a href="http://sunsite.unc.edu/LDP/HOWTO/">http://sunsite.unc.edu/LDP/HOWTO</a> Look for the
ones that refer to "PPP" and "ISP."
<p> Hope all of that helps.
<p>--
Jim
<p><hr><p>
<!--================================================================-->
<a name="command"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
Linux Command Line Arguments
</h3>
<P> <B>
From: Ronald B. Simon <a href="mailto:rbsimon@anet.bna.boeing.com">ronald.b.simon@boeing.com</a>
</B><p><B>Where can I find a list of the linux boot command line arguments?
e-mail addresses:
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
Look in the following HOW-TO document:
BootPrompt HOWTO
<a href="http://sunsite.unc.edu/LDP/HOWTO/BootPrompt-HOWTO.html">http://sunsite.unc.edu/LDP/HOWTO/BootPrompt-HOWTO.html</a>
<p>
--
Jim
<p><hr><p>
<!--================================================================-->
<a name="crash"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
More Random Crashes
</h3>
<P> <B>
Date: Fri, 01 Aug 1997 14:40:06 -0700<br>
From: sloth <a href="mailto:sloth7@hotmail.com">sloth7@hotmail.com</a>
</B><p><B>Hi, I wrote to you a while ago with a problem regarding random crashes
while installing Linux... I recently tried again, with exactly the same
hardware but a different hard disk and the whole thing worked fine.
unfortunately, the hdd i used was only and 80mb conner :). The hard disk
i want to use is a 2.1 gb Quantum Fireball. When I try on this hard disk
the computer locks up at a different place each time during the
installation ( but only when it is decompressing the files). I have an
IDE Hard disk controller.
</B><p><B>h/w list:
</B><ul><B>
</B><li><B>Intel Pentium 150 CPU
</B><li><B>Intel Triton VX m/b
</B><li><B>S3 Virge 3d graphics card
</B><li><B>16mb EDO RAM
</B><li><B>2.1gb Quantum Fireball
</B><li><B>onboard (ide) hdd controller
</B><li><B>24x IDE CDROM
</B></ul><B>
</B><p><B>any help would be much appreciated.
</B><p><B>cheers, sloth...
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
This new information about your situation suggests two
possibilities:
<p> 1) Your HD is bad -- possibly it has some bad
sectors that the drive electronics haven't
mapped out, or possibly it's something more
subtle.
<p> 2) Your controller (IDE) is incompatible with your
HD and/or the combination of your HD and CD drive.
<p> Some notes:
<p> Any IDE drive that's over 540Mb requires an EIDE (enhanced IDE)
controller/BIOS. There have been cases where specific IDE
devices weren't compatible with one another -- where a particular
combination of devices couldn't share the same IDE channel.
<p> So, try getting a new EIDE controller and disabling the
interface on the motherboard (or configuring the new on as
a "secondary" IDE channel. Try running the two devices on the
new EIDE controller if you can get it installed as the primary
(but don't blindly trust the motherboard documentation -- I've
heard that some of the "disable me" settings on some boards just
don't work). Then try running the CD-ROM drive and the hard disk
on separate channels (controllers).
<p> If you can get a copy of Spinrite or the Norton Utilities for
DOS then you might install a small DOS partition and run that on
your Fireball. It might be able to map out any bad sectors.
<p> If you get a new controller (which will be less expensive then
buying either of the software packages I just mentioned) I'd
try a a QuickPath Portfolio or a GSI brand multi-funtion card with
4 high speed (16550 UART) serial ports. The QuickPath is an ISA
card (rather than taking up one of your PCI slots for a set of
relatively slow interfaces) and is what I'm using in a couple of
my machines here. It combines floppy, four serial, two parallel,
two IDE channels and a game port (for 13 devices in all).
<p> Hope that helps. Unfortunately the diversity and cheapness
of PC hardware results in a diversity of inexplicable
incompatibilities and a common "cheapness" in quality that's
imposed by the competition. So, as much as I hate to recommend
"black magic" experiments in new hardware -- it's frequently the
most effective approach.
<p>
--
Jim
<p><hr><p>
<!--================================================================-->
<a name="disk"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
More on Disk Defrag
</h3>
<P> <B>
Date: Mon, 4 Aug 1997 20:27:11 +0200<br>
From: Markus Enzenberger <a href="mailto:Markus.Enzenberger@physik.uni-muenchen.de">Markus.Enzenberger@physik.uni-muenchen.de</a>
</B><P><B>...them in any Linux books that I have consulted. Is disk degragmentation
not needed in maintaining a Linux file system?
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
No, disk fragmentaion is a particular problem of the DOS FAT file system
and its descendants. You can see the fragmentation status of one your
partitions by running the e2fsck file system check program as root
on an unmounted partition. It is run every boot time too. It will report
the amount of non-contiguous files.
<p>
- Markus
<p><hr><p>
<!--================================================================-->
<a name="xwind"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
X-Windows is Crashing
</h3>
<P> <B>
Date: Sun, 13 Jul 1997 19:34:12 -0700<br>
From: Gerramie Dinsel<a href="mailto:gerr@weaveworld.unix.net">gerr@weaveworld.unix.net</a>
</B><p><B>Hello. I am searching all over for an answer or a pointer to this
problem:
</B><p><B>I upgraded my memory from 18 megs to 48. Now, X-Windows crashes on me
when I load FVWM2.. Odd, because XDM loads fine and will sit there,
waiting, without crashing for as long as you want. Also, console mode
works wonderfully...
</B><p><B>Can you offer any help?
Gerramie Dinsel
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
The first guess might be that the new memory is bad --
and that you normal (console) usage -- and the overhead of
xdm just doesn't "land" on the bad chips.
<p> One way to test this would be to do something from
console mode that will use *a lot* of memory. make's
-j switch (to parallelize as many gcc processes as
memory allows) is a good way to test for this sort
of thing. Just make a new kernel (no need to even to
an install of it -- just the make is fine).
<p> If that runs O.K. than we have linked the problem
X -- possibly to any graphical use of the card beyond
xdm's. So we try to run X with no window manager and
a minimal configuration file (no setting of special
root images like xli, xloadimage, or xsetroot, no
-16bpp or any of that).
<p> It could be that your video card uses a region of
address space (a video frame buffer). Look carefully
in the configuration settings, or call the manufacturer's
tech support. That's the most likely problem.
<p> If you have access to another, simpler video card -- try swapping
it in and seeing if that helps. If it does than you need to
reconfigure that video card or use one that's better behaved.
<p> If that doesn't help then it's just anyone's guess what's
happening. Try rearranging the adapters in your card cage -- it
may be that the video card is emanating some noise or crosstalk
that's affecting your RAM. Re-arranging adapters used to be
a time honored sport among PC technicians. I think it's more
rare in the PCI era -- but you don't even mention what sort of
bus your using -- and I have no information about your hardware.
Besides -- it can't hurt.
<p> If it still doesn't work try switching to 32Mb. This might
be some weird chipset bug on your amount of RAM. More systems
work with 16 or 32Mb of RAM than with 24 or 48Mb.
<p> There are a plethora of parameters you can pass to the
kernel for excluding specific memory address ranges from
its use. They might help -- but I'd hate to have to experiment
with them.
<p>
--
Jim
<p><hr><p>
<!--================================================================-->
<a name="lynx"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
Lynx and Frames
</h3>
<P> <B>
Date: Tue, 05 Aug 1997 02:48:26 -0700<br>
From: Scott <a href="mailto:omegam@COMMUNIQUE.NET">omegam@COMMUNIQUE.NET</a>
</B><p><B>Hey Jim,
Caught this quote in your article:
</B><p><B><I> (Warning for Lynx users -- both of these sites use frames and
neither bothers to put real content in
the "noframes" section -- Yech!) </I>
</B><p><B>Current versions of lynx support frames and tables in a fairly nice and
elegant fashion. They even handle cookies.
</B><p><B>Check out <a href="http://lynx.browser.org">http://lynx.browser.org</a>
</B><p><B>Just thought you should know. Sure, I use Netscape for some of my
browsing and I hope to begin using Mnemonic soon. But for really fast,
heavy-content oriented browsing, lynx on the console or in a color-xterm
does the trick.
</B><p><B>Scott
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
Oh, I know that Lynx 2.7.1 can handle frames, by simply
showing you a list of the available frames as a set of hot
points at the top of the rendered page. I use Lynx for almost
all of my web browsing.
<p> The problem is that the HTML editors used by many sites don't
put meaningful names on the frames so you get a list of:
frame01.html, frame02.html, etc. instead of something like:
navigation.html, main.html, toolbar.html etc.
<p> It's as irritating as those sites that use large tableaus of
image icons with no Alt="" attributes or imagemaps that with
no sane information in the .map file. (The current Lynx can
also handle most types of image maps.
<p>
--
Jim
<p><hr><p>
<!--================================================================-->
<a name="ftpd"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
More on ftpd
</h3>
<P> <B>
Date: Tue, 05 Aug 1997 01:59:18 -0700<br>
From: Benjamin Peikes <a href="mailto:benp@npsa.com">benp@npsa.com</a>
</B><p>Jim,<B>
</B><p><B>I am currently trying to set up some user accounts on our webserver
so that other people working on their sites can ftp their files up
and down easily. I am using wu.ftpd and have set up the line
</B><pre><B>guestgroup ftponly</B></pre><B>
in /etc/ftpaccess. I have also added the group into /etc/group and
added the users name to the group. The problems is that everything
seems to work correctly except that ls and dir return nothing during
an ftp session.
</B><ol><B>
</B><li><B>ftpd chroot's to the correct directory.
</B><li><B>ftpd changes to the correct home directory.
</B><li><B>you can upload and download files without any problems if you know
the name of the files you want.
</B><li><B>I have made the directories world rwx just to make sure it wasn't
a permissions problem.
</B></ol><B>
</B><p><B>I'm so close that it's driving me nuts. The main problem arises
when people need to transfer entire directories. Most of them are
using GUI driven ftp clients and the lack of directory listings kill
those clients. I know there must be a simple solution. Any help would
be great.
</B><p><B> Ben
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
You're probably having problems with the shared libraries
or devices that are typically required by the ls command.
Some version of ls require that you have a /dev/null and/or
a /dev/tcp in order to work properly. Most versions of ls
require some shared libraries and all of them require the
existence of some of /etc/passwd and /etc/group files (even
with completely fictional data in them) in order to resolve
UID numbers into symbolic ownership information to display in
long listings.
<p> For real information about setting up wu-ftpd on any platform
look at the following resources:
<a href="http://www.landfield.com/wu-ftpd/">http://www.landfield.com/wu-ftpd/</a>
<a href="http://www.cetis.hvu.nl/~koos/wu-ftpd-faq.html">http://www.cetis.hvu.nl/~koos/we-ftpd-faq.html</a>
(Or, <a href="mailto:wu-ftpd-faq@pizza.hvu.nl">send
mail</a> with subject of
"send faq" no quotes, body ignored).
<p> ... and information about the guestgroups feature in particular
can be found at:
<a href="http://www.landfield.com/wu-ftpd/guest-howto.html">http://www.landfield.com/wu-rtpd/guest-howto.html</a>
<p> ... or
<a href="ftp://ftp.fni.com/pub/wu-ftpd/guest-howto">ftp://ftp/fni/com/pub/wu-ftpd/guest-howto</a>
<p> A document describing virtual ftp servers:
<a href="http://www.westnet.com/providers/multi-wu-ftpd.txt">http://www.westnet.com/providers/multi-wu-ftpd.txt</a>
<p> Ftpaccess on virtual ftp servers
<a href="ftp://ftp.meme.com/pub/software/wu-ftpd-2.4.2/README.ALT.FTPACCESS">ftp://ftp.meme.com/pub/software/wu-ftpd-2.4.2/README.ALT.FTPACCESS</a>
<p>Hope that covers it.
<p>
--
Jim
<p><hr><p>
<!--================================================================-->
<a name="dns"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
DNS Problem
</h3>
<P> <B>
Date: Mon, 04 Aug 1997 18:31:36 -0700<br>
From: Dr Ceezaer <a href="mailto:ceezaer@cyberspace.org">ceezaer@cyberspace.org</a>
</B><p><B>(Ping doesn't work -- but /etc/resolv.conf and /etc/hosts.conf
are correct and nslookup works).
</B><p><B>It used to work before I upgraded my library files (/lib and /usr/lib) so I
don't think there is an error in /et/resolv.cfg
</B><p><B>Well... I've solved the problem. First I re-installed Linux on a small 120
MB harddisk. By comparing all relevant directories I found that I had a file
called libc.so.5 (no symlink) in /usr/X11R6/lib plus the normal one in /lib.
By removing the file /usr/X11R6/lib/libc.so.5 it all works again :)
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
Ahh the mysteries of the shared libraries. I've always
wondered how the dynamic loading code searches for these .so
(shared object) files. However I've never wondered enough to
leave stray copies of them laying around.
<P><B><img align=bottom alt=" " src="../gx/ques.gif">
Well... I would need such a HOWTO, I didn't even got chroot to run...
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
The only real trick is to do a 'cd' before trying to execute
the command -- otherwise your process is very confused becuase
it can't access its current working directory (cwd).
<p> The other problem is that your target program must be
contained in the chroot tree with any shared libraries
and usually it will need a set of /etc/ files including the
termcap and maybe a set of /usr/lib/terminfo files.
<p>
--
Jim
<p><hr><p>
<!--================================================================-->
<a name="sendmail"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
Sendmail
</h3>
<P> <B>
Date:Sun, 10 aug 1997 14:4457 -0700<br>
From: Stephen P. Smith <a href="mailto:ssmith1@wilma.bcasd.az.honeywell.com">ssmith1@vilma.bcasd.az.honeywell.com</a>
</B><p><B>When I send mail (using the mail program) to someone my reply to address
is wrong.
What sendmail is sending is account@computername.isp.com
What I want is popaccount@isp.com
What do I need to change to fix this
</B><p><B>Stephen Smith
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
You use the "masquerade" feature in your local sendmail
configuration. I recommend that you use the m4 macro
package to reate a new sendmail configuration.
<p> First copy the old configuration. I like to use RCS --
the revision control system to track changes to my
configuration files. Here's how you'd do that:
<p> (As root)
<pre> # cd /etc
# mkdir RCS
(unless you already have one)
# ci sendmail.cf
(checks the cf file into the RCS directory)
# co -l sendmail.cf
(checks it back out, locked for editing)
</pre>
<p> Now you want to create a sendmail "mc" file. This is a file
that uses sendmail specific macros -- which is then processed
by the m4 program to generate the full sendmail.cf. A typical
sendmail.cf is over a 1000 lines long -- a typical "mc" file
is less than 20.
<p> Under my Red Hat installation the sample "mc" files are located
in /usr/lib/sendmail-cf/cf/. You can put yours there, or
you might use /usr/local/lib/sendmail (and perhaps add a symlink
under the other path). This helps maintain the separation between
your local changes and the distribution's files "as shipped."
<p> I name my "mc" files after my hostnames -- so mine is "antares.mc."
It looks like this:
<pre>
divert(-1)
include(`../m4/cf.m4')
VERSIONID(`@(#)antares.uucp.mc .9 (JTD) 8/11/95')
OSTYPE(`linux')
FEATURE(nodns)
FEATURE(nocanonify)
FEATURE(mailertable)
FEATURE(local_procmail)
FEATURE(allmasquerade)
FEATURE(always_add_domain)
FEATURE(masquerade_envelope)
MAILER(local)
MAILER(smtp)
MAILER(uucp)
MASQUERADE_AS(starshine.org)
SITECONFIG(uucp.antares, starshine.org, U)
define(`UUCP_RELAY', a2i)
define(`UUCPNAME', starshine)
define(`UUCPNODES', a2i)
define(`RELAY_HOST', a2i)
define(`RELAY_MAILER',uucp)
define(`SMART_HOST', uucp-dom:mailer)
define(`PSEUDONYMS', starshine|antares|antares.starshine.org|starshine.org)
undefine(`BITNET_RELAY')
</pre>
<p> I've seen some of these that end each line with a 'dnl' --
which is a macro to "do newline" -- I don't bother with that.
<p> You'll want to ignore all the UUCP references and my
SITECONFIG line (mine is also a UUCP reference -- so yours
will be different -- preserve whatever is in the samples that
mathc your current configuration).
<p> What your interested in here is the various "masquerade" lines.
Now you'd just 'cd' to the directory where you've created this
"mc" file and issue a command like:
<pre> m4 < $MYFILE > /etc/sendmail.cf
</pre>
<p> (where you replace $MYFILE with whatever you named your "mc"
file, of course).
<p> It's also possible to to simply add a line like:
<pre>DMisp.com</pre>
<p> ... directly to your /etc/sendmail.cf.
DM "defines masquerading" to be for "isp.com" (from your
earlier example). This is easier, on the one hand --
but learning the m4 configuration method will serve you
well if you ever have to do upgrades to your sendmail --
and it's a valuable skill if you ever have to administer
Unix systems as (or as part of) your work.
<p> There are a variety of HOWTO's on configuring your mail
to work well with your ISP. I don't have my PPP connection
up at the moment -- but you should search the SSC web site
(http://www.ssc.com) for the the HOWTO archive and look for
the strings "ISP" and "mail."
<p>
--
Jim
<p><hr><p>
<!--================================================================-->
<a name="server"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
Linux PPP Server
</h3>
<P> <B>
Date: Sun, 10 Aug 1997 05:34:45 -0700<br>
From: <a href="mailto:sengir@ozemail.com.au">sengir@ozemail.com.au</a>
</B><p><B>I have a Linux PPP server but I can not get my Windows95
client to do the "automatic" login. Sure, I can get it
all to work if I check "bring up terminal window after connecting".
</B><p><B>All I have is the login: prompt, followed by the Password: prompt
then right into PPP.
</B><p><B>What gives ?
</B><p><B>TIA<br>
-Rob
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
Here's a URL that talks about getting Linux
mgetty to work with Microsoft's infamous "AutoPPP":
<p><a href="http://www.buoy.com/isp/mgetty.html">ISP Resources - mgetty info(AutoPPP)</A>
<p> For more general information about mgetty look at:
<a href="http://www.leo.org/~doering/mgetty/">Mgetty + Sendfax
Documentation Centre</a>
<p>--
Jim
<p><hr><p>
<!--================================================================-->
<a name="emulator"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
Linux/Unix Emulator
</h3>
<P> <B>
Date: Sun, 10 Aug 1997 05:30:18 -0700<BR>
From: Jun Liu <a href="mailto:stefan@public.sta.net.cn">stefan@public.sta.net.cn</a>
</B><p><B>Hi, Dear James,
</B><p><B>First I'd like express my gratitude for your great work on the Linux
Gazette.
But for the Linux/Unix Emulator, I think you're somehow wrong. Actually
there do exist at least one such product as far as I know. When I was
staying in Japan, I've learned there're quite some people there use a
software called BOW (namely BSD on Windows ), which is a BSD emulator for
Windows. Check out <a href="http://www.ascii.co.jp/pb/superascii/bow">http://www.ascii.co.jp/superascii/bow</a> if you do know
Japanese. In short, this is a BSD kernel emulator for 4.4BSD-Lite based
BSD Unix program. It's said most BSD binaries (x86 certainly,character
mode applications only, no X, no debuggers like gdb) can be run
unmodified.
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
Actually, there has been quite a bit of work on supporting
Unix under NT. Cygnus Support (http://www.cygnus.com) has
made quite a bit of progress with their
<a href="http://www.cygnus.com/misc/gnu-win32/">GNU-Win32
Project</a>
</B><p><B> A couple of other sources worth noting are:
<a href="http://www.softway.com/OpenNT/20server.htm">OpenNT 2.0 Server Data
Sheet</a>
<a href="http://nentug.org/unix-to-nt/">UNIX to NT Resource Center</a>
</B><p><B> There was also a paper presented at the Anaheim USENIX
conference this year:
<ul>
<li>Title: Porting UNIX to Windows NT
<li>Author: David G. Korn
<li>Pages: 43-57
<li>Publisher: USENIX
<li>Proceedings: 1997 Annual Technical Conference
<li>Date: January 6-10, 1997
<li>Location: Anaheim, CA
<li>Institution: AT&T Labs-Research
</ul>
</B><p><B>The advantages are, you have the rich development environment from Unix,
and the nice( ? ) UI from Windows as well as lots of Windows applications
around all at the same time. It's said BOW Version 1.5 which is Windows95
compatible, is already published last year in May as a book and available
in Japanese bookstores,
priced at 9,800 yen with one floppy disk and one CD-ROM.
</B><p><B>Hope this can be helpful.
</B><p><B>Best regards.<br>
Stefan
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
Again, in the article to which you refer I was asking
what the original person was asking for. Many Unix packages
have been ported to NT, Windows '95, and DOS (emacs, perl,
awk, most of the simple commands like grep, cp, find, and
a couple of shells: Korn, bash) -- and it would certainly be
possible to host some binaries under (ELF, iBCS).
<p> At what point to NT become Unix?
<p>
--
Jim
<p><hr><p>
<!--================================================================-->
<a name="lilo"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
LILO Concerns
</h3>
<P> <B>
Date: Sun, 10 Aug 1997 03:50:35 -0700<br>
From: Tibs <a href="mailto:tjf1@acpub.duke.edu">tjf1@acpub.duke.edu</a><br>
</B><p><B>I have been looking all over for an answer to my linux question...nobody
seems able to help so I thought I'd ask you (liked the LG web stuff very
much). I am about to take the plunge and install linux but I am
concerned about how LILO will work on my system. I have two IDE drives
on my system. The first is 1 gig and I have DOS, Win95, etc. on it and
that's what I boot to. The second is divided into two 1.5 gig
partitions, and 1 500 meg partition. I planned on putting linux on that
last 500 meg partition.
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
First: you'll want to learn how to use paragraphs.
Break your question down into short steps so we can
read it (particularly when we're doing the reading at
3:30 in the morning after hacking all day)
<P><B><img align=bottom alt=" " src="../gx/ques.gif">
.... The problem is that in order for my computer to
recognize the full 3.5 gig capacity of the second hard drive, the hard
drive installation floppy (it's a Maxtor) installed something called
EZ-BIOS. So booting to DOS or Win95 now works and my BIOS recognizes all
3.5 gigs of the space. When I boot to a floppy I have to use the EZ-BIOS
"boot to a:" option otherwise I can only access the first partition on
the second drive. So when I install linux and add LILO, will LILO start
doing stuff after the EZ-BIOS stuff loads? If so then it is not a
problem but if LILO starts before EZ-BIOS does it's thing, then I don't
think I'll be able to access my 500 meg partition. And since that's
wherelinux would be, that would be a bit of a problem.
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
You're using an alternative master boot program which
will be incompatible with any other boot software.
<p> You should use LOADLIN and forget all about LILO.
<p> I've written about LOADLIN several times in this column --
so please look back through some of the pack issues for details.
<P><B><img align=bottom alt=" " src="../gx/ques.gif">
So I guess my question would be:
1. do you know anything about this EZ-BIOS stuff and it's compatibility
with linux (the Maxtor people aren't helping with linux questions)
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
The EZ-BIOS and the old Ontrack Disk Manager and similar
drivers were originally created to allow DOS to see larger
partitions (which they did by hooking into the BIOS Int 13H
disk access routines before DOS was loaded -- by replacing the
MBR). They have always been a bad idea.
<p> Now that DOS supports partitions larger than 32Mb these
programs have a different purpose -- to allow older
systems to see IDE drives that are larger than 512Mb.
The BIOS interface only supports a maximum of 1024 cylinders
of up to 64 sectors each. A typical drive is less than 16 heads.
This "geometry" gives a maximum of about 528Mb. It's possible
to "lie" to some BIOS' and double the number of heads -- or
even go up do 255 "virtual heads" -- the drive electronics will
simply translate for you.
<p> Essentially this is how SCSI and EIDE drives give you access to
larger disks (up to about 9Gb).
<p> Your other alternative is to get an EIDE controller and get
rid of the non-standard software (sofware which isn't supported
under OS that I know of, Linux, any Unix, FreeBSD, NT,
OS/2 or anything other than DOS).
<B><P><img align=bottom alt=" " src="../gx/ques.gif">
2. is there some workaround that would still let me use linux if EZ-BIOS
would be a problem (like using a boot floppy everytime I wanted to use
linux, or something like that)
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
You can probably just use LOADLIN. However you might have to
cook up some weird boot time parameters (you can store them
in the bathc file that invokes LOADLIN) to tell the kernel what
the drive geometry really is -- so it doesn't step on anything.
<p> Here are the two HOWTO documents you want to read:
<p><a href="http://sunsite.unc.edu/LDP/HOWTO/mini/Large-Disk">Large Disk
mini-HOWTO</a>
<p><a href="http://sunsite.unc.edu/LDP/HOWTO/mini/Loadlin+Win95">Loadlin+Win95
mini-HOWTO</a>
<p>--
Jim
<p><hr><p>
<!--================================================================-->
<a name="crypt"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
Crypt
</h3>
<P> <B>
Date: Fri, 08 Aug 1997 20:47:11 -0700<br>
From: David Saccon, <a href="mailto:dasac@speed.it">dasac@speed.it</a><br>
</B><p><B>Hi; I'm a Linux enthusiast bla bla bla, compliments for the
good work, etc etc.
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
Well, charmed I'm sure!
<P><B><img align=bottom alt=" " src="../gx/ques.gif">
I don't know if an e-mail to this address is the right way to
ask you a question.
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
It isn't really -- but most of the readers of Linux
Gazette's "The Answer Guy" column haven't see the "tag@"
address that I currently prefer.
<P><B><img align=bottom alt=" " src="../gx/ques.gif">
Please feel free to get rid of this mail if it bugs you.
Anyway, my question is: where can I find an implementation of
the fine tool "crypt" for Linux ?
You know, "crypt &lt;myfile &gt;myfile.x password", and back to the
clear text the same way.
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
I'm not sure that the traditional Unix 'crypt' command is
all that "fine." I'd suggest that you obtain a copy of
PGP from one of the international sites that carry it.
<p> (Please don't obtain it from any of my "free" fellow
U.S. citizens -- since it would be illegal for them to
exercise this particular form of free speech at this time.
I'd like to apologize for the ludicrous attitude my government
takes with regards to cryptographic software -- feel free to
refer to the "Electronic Freedom Frontier" (http://www.eff.org)
for more information about that).
<P><B><img align=bottom alt=" " src="../gx/ques.gif">
I haunted the internet for days but couldn't find it.
I also tried something like this:
</B><pre><B>
include "stdio.h"
include "unistd.h"
void main(int argc, char ** argv )
{
puts(crypt(argv[1], argv[2]))
}
</B></pre><B>
but it doesn't work the same way.
</B><p><B>Help!<br>
Thank you<br>
Davide Saccon
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
There is a library function named "crypt" which is technically
a "hash" rather than a cryptographic function -- it's used to
compute the hash of a password for comparison to that which is
stored in the second field each entry in the /etc/passwd file.
<p> I've heard that the program named 'crypt' varies from one Unix
implementation to another. I think its currently not included
in many Linux distributions to the export (U.S. ITAR and related)
restrictions to which I alluded earlier. Since many of the
companies that produce these distributions are U.S. they would
have to ensure that their products were for "domestic use" only
if they were to include this on their CD's and in their FTP sites.
<p> Here are a few sites I picked off of Yahoo!
<a href="http://www.ifi.uio.no/pgp/FAQ.shtml">International PGP FAQ</a>
<a href="http://www.serve.com/nimrod/pgp.html">Guida Pratica a PGP</a>
Guida Pratica a PGP
<a href="http://www.ifi.uio.no/pgp/doc/g_pgp952.htm">PGP User's Guide (in
Italian -- 250K)</a>
<a href="http://www.agora.stm.it/N.Ferri/crypto.htm">The Crypto Chamber --
Italian</a>
<a href="ftp://ftp.ox.ac.uk/pub/crypto/cryptanalysis/cbw.tar.gz">Cryptographer's
WorkBench</a>.
<p> There are other strong cryptographic products available
internationally for other purposes. I think the new Linux
"TCFS" (transparent cryptographic filesystem) is being done
in Italy. TCFS is apparently similar to Matt Blaze's research
on CFS -- it allows a Linux admin to create filesystems that
are encrypted in such a away that users can have confidence that
no other user access their files. Given its design is should be
difficult even for the root user to compromise the cryptographic
integrity of any local user -- and it should be impractical for
remote systems.
<p> Here's some more links for that:
<a href="http://www.globenet.it/~ermmau/tcfs/">Transparent Cryptographic
File System Project Page</a>
<a href="http://mikonos.dia.unisa.it/tcfs">TCFS</a>
<a href="http://www.globenet.it/~ermmau/tcfs/tcfs-faq.html">TCFA FAQ
v1.7.7</a>
<p> Come to think of it STEL (a secure telnet) was also done in
Italy. Seems that a lot of work on cryptography is coming out
of your country. Obviously your government hasn't been
interferring in this work. If you'd like to look at the sources
for STEL I'd FTP over to ftp://idea.sec.dsi.unimi.it/cert-it/
<p> Another set of useful cryptographic resources are in Eric A.
Young's free implementation of Netscape's SSL (secure sockets
layer) specification and a set of related applications
(like ssltelnet and sslftp):
SSLeay: SSLeay and SSLapps FAQ
<a href="http://psych.psy.uq.oz.au/~ftp/Crypto/">SSLeay: SSLeayand SSLapps
FAQ</a>
<p> (This set of pages is an excellent resource for anyone that
wants to learn anything about SSL).
<p> Eric's work was instrumental in the development of the
Stronghold web server by C2 Software Inc. (http://www.c2.net)
(I recently published an interview with C2's founder, Sameer
Parekh, in Linux Journal, if your interested).
<p> And, of course, no discussion of Internet cryptography tools
would be complete without a mention of Tatu Ylongen's SSH
<a href="http://www.cs.hut.fi/ssh">ssh (Secure Shell)</a>
<a href="http://www.uni-karlsruhe.de/~ig25/ssh-faq/">ssh FAQ</a>
<p>--
Jim
<p><hr><p>
<!--================================================================-->
<a name="apache"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
Apache 1.2.1
</h3>
<P> <B>
Date: Mon, 11 Aug 1997 13:53:14 -0700<br>
From: Alf Stockton <a href="mailto:stockton@acenet.co.za">stockton@acenet.co.za</a><br>
I am playing with Apache 1.2.1 and have it running well except that it
won't run cgi scripts.
If I give the full path in the command line of the browser the CGIs run
fine but the server cannot/does not run these CGIs when I expect it to.
Where can I turn for help? The Apache team don't appear too interested.
I suspect that one of my config files is wrong but don't know enough to
tell which.
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
I wouldn't necessarily say that the Apache team isn't
"interested." However, they far more interested in
providing the software than in answering questions about
it.
<p> It sounds like you don't have your "ScriptAlias" set up
correctly -- or you're trying to access a CGI script that
isn't stored in one of the proper "ScriptAlias" directories.
<p> Here are links to the relevant documentation pages at the
Apache site (http://www.apache.org):
<p> Apache: Configuration: ScriptAlias
<a href="http://www.apache.org/docs/mod/mod_alias.html#scriptalias">http://www.apache.org/docs/mod/mod_alias.html#scriptalias</a>
<P> Apache: FAQ: How do I enable CGI execution in directories
other than the ScriptAlias?
<a href="http://www.apache.org/docs/misc/FAQ.html#CGIoutsideScriptAlias">http://www.apache.org/docs/misc/FAQ.html#CGIoutsideScriptAlias</a>
<p> Another possibility is that you have built it with no CGI
support. Apache has many compile-time configuration options
-- include a large list of "modules" that can ben enabled or
disabled. However I'm sure that it would take some work to
build Apache with no CGI support -- so I think this possibility
is remote.
<p>--
Jim
<p><hr><p>
<!--================================================================-->
<a name="redhat"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
Red Hat Questions
</h3>
<P> <B>
From: Brent Johnson <a href="mailto:brent@saturn.msstate.edu">brent@saturn.msstate.edu</a>
</B><p><B>So are you the answer guy and can you answer a very important question for
me?
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
I appear to have been dubbed "The Answer Guy" (it wasn't
a self-appointment -- but I did volunteer for it).
<p> I can certainly answer any question. Answering it correctly
and usefully are not as sure a bet -- but I'll try.
<P><B><img align=bottom alt=" " src="../gx/ques.gif">
I first heard about RedHat's Linux distribution about a year ago and there
was no way Slackware could compete to the easy installation procedure,
RPMS, and other great features included in RedHat.
</B><p><B>But, ever since I moved to RedHat Ive had a terrible gcc compiler problem.
This has happened to me on two different machines... on the first Id
assumed it was some memory problem (as in hardware), but now Im on a
totally different machine that has (or shouldnt have) any memory problem.
</B><p><B>Everytime I try and compile anything (Apache 1.2.1 for example)... it gets
to about the 3rd or 4th .c file, and it bombs out with the following
error:
</B><pre><B>gcc -c -Iregex -O2 -DLINUX=2 util_date.c
gcc -c -Iregex -O2 -DLINUX=2 util_snprintf.c
gcc: Internal compiler error: program cc1 got fatal signal 11
make: *** [util_snprintf.o] Error 1</B></pre><B>
</B><p><B>It happens at different times on different .c files when compiling
different things. Any help would be greatly appreciated... a Unix system
with a defective compiler or defective hardware is almost useless!
</B><p><B>- Brent
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
I notice that you haven't told me *which version* of Red Hat
you're working with. However I've used 3.03, 4.0, 4.1, and
4.2 -- and I think I remember playing with an earlier one before
3.03 and I never saw this behavior from gcc.
<p> I did get it from my original copy of minicom anytime I was
running in an extended video mode and trying to use the
dialer (and not when issuing the same dialing function as
a direct ATDT command from the terminal window). In this
case I suspect there was a bug in the ncurses calls being
made by minicom. In any event I switched to CKermit and
forgot all about it.
<p> In your case the signal 11 (SEGV) is probably not caused
by curses/ncurses calls.
<p> Do you have a swap partition or file? If so, have you tried
disabling it (possibly creating a new one temporarily)? If
you have a defect on the disk you could get a SEGV from some
piece of data/code that gets swapped out, read back in
(with errors) and subsequently used by the running process.
<p> If you don't have a swap partition or file you might just be
running out of RAM completely. gcc does use up quite a bit
of memory -- so I'd suggest at least 32Mb virtual memory
(RAM + swap) available when running it (you could certainly
ask the FSF for more specific recommendations -- this is
just my unsubstantiated and untested suggestion).
<p> When you installed, did you let Red Hat's install routine
perform thorough block checking while it was making filesystems?
If not, try re-installing and enabling that (in case you hit
some bad spots on your disk and you have corrupted gcc
binaries).
<p> This is extremely unlikely to be related to your distribution,
but you could try installing Slackware to see if its gcc
works on this system -- or you could try booting up in
single user mode and just run a few test "make's" from
a simple shell line (no emacs M-x shell mode, no X Windows,
no "integrated dev. environment" nothing else running).
<p> If you still get SEGV's then, you want to find some other
sort of memory intensive program to run as a test -- to see
what else will die. It may be worth extracting the RAM and
taking it to a good hardware tester -- and/or removing any
ethernet cards or unecessary adapters for other tests.
<p> These sorts of things can be very frustrating to track down
regardless of OS. If you have a copy of DOS and an old copy
of Norton Utilities (version 8 or later) you could boot that
up and run NDIAGS.EXE. There are several other diagnostics
packages that were available before it -- but NU is still my
personal favorite untill the Linux crowd does up a suite of
them. Unfortunately the results of any software diagnostics
package aren't definitive -- they can detect trouble -- but
they can't "prove" that there isn't any hardware problem.
<p> I suppose, for some systems, particularly some 386's and
386SX's, you might also try twiddling the CMOS "wait states"
settings. Those used to make a difference -- particularly
with earlier generations of "3-chip" SIMM's. Apparently
in the early attempts to use SIMM's with three chips
(two four bit chips and a parity bit chip) there were some
slight timing differences between the "signal settling"
characteristics -- so the parity bit wouldn't "settle"
before the system was trying to read the memory. This resulted
in parity errors if the systems were set for "zero wait states"
-- and was generally solved by changing the CMOS settings.
<p> (I've never heard of a Pentium system or any system using
72-pin SIMM's having these problems -- but that doesn't
mean it's not worth looking in your "advanced" CMOS and
trying some experiments therein).
<p> I hope some of this helps.
<p>
--
Jim
<p><hr><p>
<!--================================================================-->
<a name="internet"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
PPP and Internet MCI
</h3>
<P> <B>
From: Demosthenes <a href="mailto:radams@capaccess.org">radams@capaccess.org</a><br>
Subject: Re: PPP and InternetMCI
</B><p><B>Hey there, I've been reading through your column from August in the
Linux Gazette, and ran across the gentleman's question regarding GTE's
internet services.
</B><p><B>I'm trying to switch over to MCI from a local ISP, and I'm having some
of the oddest connection problems. I use PAP currently with my local
ISP, and MCI is supposed to use PAP/CHAP (one, the other, or both
:P). I beleive i have everything setup properly, as I don't get any
rejections from PAP/CHAP, but after a few seconds of modem activity
with the server, MCI just hangs up. I did misspell something before,
and got a PAP rejection, and I've got full debugging logs regarding
the connection, but I can't make much sense of them. I know the server
isn't asking for MS-CHAP (chap 80, vs chap 05). It looks like it dies
during the configuration. I'm not sure.
</B><p><B>Do you have any information regarding connecting to InternetMCI via
Linux? MCI tech support is clueless, and I can't even get someone that
knows how their own software works on the phone.
</B><p><B>Any help would be highly appreciated, and I'd be more than glad to
share my debugging logs if you think they will help.
</B><p><B>Thanks again!
</B><p><B>Russell Adams
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
My first impulse is to say "vote with your feet."
Fire off a polite, assertive, note to their VP of Customer
Service and go find a Linux/Unix friendly ISP with quality
tech support (and maybe spend a little more in the process).
<p> My provider isn't the cheapest -- and isn't even the friendliest
-- but they understand Unix and they provide quality service
(refusing to structure their rates to "compete" with an
unreasonable "quality of service" -- i.e. I get few busy signals).
<p> That bit of non-technical advice aside I'd ask:
What are your MTU and related parameters?
<p> You could send the logging output -- but it would probably
be as incomprehensible to me as it is to you. I've never
set up a PAP/CHAP system (yet). However I'll look at them
and suggest some experiments.
<p>
--
Jim
<p><hr><p>
<!--================================================================-->
<a name="auto"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
Enabling Automounter on a Linux Notebook
</h3>
<P> <B>
From: Dennis Dai <a href="mailto:gqdai@intergate.bc.ca">gqdai@intergate.bc.ca</a><br>
</B><p><B>Hi, Jim
</B><p><B>I think I need to ask you for help. My problem is:
</B><p><B>Originally I have a 1.6G HD. Last month I bought a new one (3.2G) in
order to accommodate linux and NT. I placed the swap partition in the
very last part of the new harddisk (it seems that this is a bad idea,
isn't it?) which is hdc8 and initialized it without problem. After a
while, I made a new NTFS partition for NT which resides in front of the
swap partition (I installed NT system on one of my original HD's
partition which is hda7), then I moved some of my data on the new NTFS
partition. But after I booted up to linux, I realized that the swap
partition didn't initialized properly, so I issue a command like this:
</B><pre><B>mkswap /dev/hdc8</pre>
</B><P><B>And this was how I screwed up things. Actually the new NTFS partition
became hdc8, and the original swap partition became hdc9. Now I can't
access the new NTFS partition from NT!
</B><p><B>Immediately after I issued that command, I realized that I made a big
mistake so I issued a "free" command and it showed that the swap
partition (which is my NTFS partition) was not used.
</B><p><B>So I think I still have hope to retrieve the data on my NTFS partition.
I know they are still there, just I can't get them out.
</B><p><B>I posted this to linux newsgroups, and received some kind response that
suggested me to use linux fdisk to change the partition type to NT one.
But I did check that, it is still NTFS (actually HPFS under linux
fdisk). Others suggested me to zero out the first 512 byte of that
partition as part of the recovery, but since I am not quite familiar
with that I didn't dare to do that.
</B><p><B>So I hope you can get me out of the hole.
Thanks in advance.
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
Well, I haven't done regular data recovery for a few
years (since I left Symantec' Peter Norton Tech Support
Department). It's not something that I can do via e-mail
(or for free) -- and I don't know diddly about the internals
of NTFS (or HPFS or ext2fs for that matter).
<p> You best bet, of course, is to have recent backups from
which you can recover. I don't know why they were suggesting
that you blast the boot record (the first 512 bytes of a
partition is the "logical boot record" or "superblock" while
the first 512 bytes of a drive is the "master boot record"
or MBR). Perhaps they believe that NT will be able to
recover from this. If I was to do anything with the LBR
I'd go to a different machine, create a new NTFS partition
that was indentical in size and configuration to the one you
think you've damaged, and use a disk editor (or a Linux
dd command) to cut and paste that from the other machine onto
the allegedly damaged partition.
<p> Before doing much of that I'd suggest do a dump to tape
of the entire raw device (using 'dd'). This may allow you
to return to the current state of brokenness after you've
made unsuccessful attempts at repair.
<p> I don't recommend these procedures (disk surgery) unless
the data on that drive is very important to you (and otherwise
unreproducable) or you really like playing with hex editors.
<p> If it's of considerable financial value to you -- I'd suggested
making a dump tape, extracting the drive from the system and
sending it to a data recovery specialist.
<p>
--
Jim
<p><hr><p>
<!--================================================================-->
<a name="locks"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
X Locks Monitor
</h3>
<P> <B>
From: Gord Urquhart <a href="mailto:urquhart@Newbridge.COM">urquhart@Newbridge.COM</a><br>
</B><p><B>I have found when playing with my Xconfig I could get my monitor (MAG15)
to go into power saving state (with a resulting black monitor) when I
changed the pre and post sections of the horizontal scan line timings (I
can't remember the proper names of these), to certain values.
</B><p><B>gord u.
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
... and? ...
<p> You can also cause a monitor to permanently damage itself
if you play with those long (wrong) enough. This is well
known and noted in the XFree86 configuration file.
<p> So, what's the point of this message? Or is it just a
stray observation?
<p>
--
Jim
<p><hr><p>
<!--================================================================-->
<a name="pop"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
Pop3d That Doesn't Use /etc/passwd
</h3>
<P> <B>
From: Benjamin Peikes <a href="mailto:benp@npsa.com">benp@npsa.com</a>
</B>
<p><B>Do you know if there is a pop3d that does not use /etc/passwd?
I want to set up mail only accounts for some people but in.pop3d
that I have uses /etc/passwd. I want to set up accounts that
sendmail knows how to deliver for but I don't want to put these
people in /etc/passwd because then I have to worry about all the
other services on the machine. Have you heard of some daemon that
will do this, or a set of packages that will do this type of seperate
user management? Thanks.
</B><p><B>Ben
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
Ultimately this issue of restricting specific classes
of users to specific services on a system is goes
way beyond the particular services you pick. PAM
(the pluggable authentication modules) is supposed
to solve this problem eventually. That is already
included with recent versions of the RedHat distributions
(and with recent Solaris releases). However it is
still evolving -- so few of us have any idea how to
"do it right." (A fact which leads to an understandable
lack of confidence in recommending it).
<p> So, getting back to the original question:
<p> What POP daemon supports a user/password
database that's distinct from the one used
by other Unix services (/etc/passwd)?
<p> I've heard the rumor that this can be done in qpopper
but I'd like to confirm that. So I go to Yahoo! and
issue the "+qpopper +account" search and get:
<p> There is:
<a href="http://www.hdshq.com/fixes/mail_patch/">http://www.hdshg.com/fixes/mail_patch/</a>
<p> ... which is supposed to be a patch to qpopper to
allow this. However I couldn't connect to and I
couldn't find any mirror of it even after several
hours of trying.
<p> I traversed a number of links searching on strings
like "+pop3 +passwd +passwd +separate" and various
permuations. This was the only firm reference I found.
<p> Another approach would be to create a custom chroot
environment. This isn't as hard as it sounds. The
hard part is making your binary statically linked or
including the necessary libraries. The other thing
you'll have to consider is whether you want the POP-only
accounts to use their own "virtual mail host" (requires
an IP alias or an additional interface) or whether you
your smtpd to run in the same chroot "jail" -- then
requiring any local account holders to also use
POP (perhaps using the fetchmail client to the
"localhost" target).
<p> Here are some of the links that have more information
on mail and POP in general.
<p><a href="http://www.harker.com/sendmail/sendmail-ref-body.html">
Harker's sendmail References Page</a>
<p>Mr. Harker gives seminars and classes in sendmail
<p><a href="http://www.eudora.com/freeware/servers.html">
Free Servers from Eudora: Servers</a>
<p>Qualcomm, publishers of Eudora, also are the source
of qpopper.
<p><a href="ftp://rtfm.mit.edu/pub/usenet/comp.answers/mail/mailclient-faq">
POP/IMAP FAQ</a>
<p><a href="http://www.uwo.ca/its/ftp/pub/unix/security/passwd-suite/#Introduction">
Passwdd/Passwd -- An authentication Daemon/Client</a>
<p> This isn't mail related specfically -- but relates to
alternative authentication model -- a passwd daemon running
on a privileged TCP port via inetd. It shows examples for
supporting Eudora/APOP and using alternate passwd files.
<a href="ftp://ftp.obtuse.com/pub/smtpd">
/pub/smtpd directory -- Similar to TIS FWTK smapd</a>
<p> Running a simpler, perhaps unprivileged smtpd to toss
incoming mail into the queue is considered to be a good
idea -- for isolating sendmail (which is large, powerful,
complex, and has a long history of compromises).
<a href="http://www.qmail.org">http://www.qmail.org</a>
The qmail Page
<p> An alternative to running sendmail at all. I won't
get into this debate -- I'm just including it in this list
because I'll receive lots of unnecessary mail if I don't.
<a href="http://www.ics.uci.edu/~mh/">
MH Message Handler Home Page</a>
<p> The Rand MH is a particular mail user agent -- actually a
set of programs for working with mail from a shell command
line. There are several packages that provide full screen
interfaces to this -- including an emacs mode/package,
mh-e, which is what I use.
<a href="http://www.westnet.com/providers/">
Scripts and Patches for ISP's</a>
<a href="http://www.usenix.org/publications/library/proceedings/sec4/carson.html">4th UNIX SECURITY SYMPOSIUM</a> -- Sendmail w/o Superuser
<a href="http://www.oit.duke.edu/~mg/email/email.paper.html">
How to Get There From Here</a> -- Scaling e-mail to the enterprise
<a href="http://amelia.db.erau.edu/~andrew/server-linux/servers.html">
Linux: Server-Linux FAQ</a>
<p> I hope all of this helps.
<p>--
Jim
<p><hr><p>
<!--================================================================-->
<a name="notebook"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
Configuration of Two Ethernet Cards
</h3>
<P> <B>
From: Carlos Gonzalez Andrade <a href="mailto:cglez@cfe.gob.mx">cglez@cfe.gob.mx</a><br>
Date: Mon, 11 Aug 1997 23:40:16 -0700
</B><p><B>Hi Jim.
</B><p><B>I have a question about some problems i have while I was seting up
2 ether cards.
</B><p><B>first . the device eth1 is not recognized when I add the line
append = <tt>ether=0,0,eth1</tt> into the lilo.conf.
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
You should consider putting the I/O base address, the
IRQ, and any DMA or memory address information into
this append clause in place of those zero's.
<p> You can test these by entering them at the LILO prompt
(interactively, during boot) before editing the /etc/lilo.conf
file.
<P><B><img align=bottom alt=" " src="../gx/ques.gif">
second . What files are necesary to set up to configure
two IP address for my machine and get runing my gateway?
</B><p><B>I will apreciate your answer
</B> <P>
<img align=bottom alt=" " src="../gx/ans2.gif">
This depends on which distribution you're using and
how closely you want to stick to their configuration
conventions. Minimally all you need is a script file
(typically located under /etc/rc.d/ and invoked by the
rc.local) with calls to the 'ifconfig,' and a 'route add'
command or two. Under Red Hat's SysV init system you'd
leave your rc.d files alone and edit some file under
your /etc/sysconfig/network-scripts/ directory (ifcfg-eth0,
and ifcfg-eth1 if I recall correctly -- it should be obvious
by browsing through those files).
<p>
--
Jim
<p><hr><p>
<!--================================================================-->
<a name="console"></a>
<h3><img align=bottom alt=" " src="../gx/ques.gif">
Attaching a Console to a PC
</h3>
<P> <B>
To: Benjamin Peikes <a href="mailto:benp@npsa.com">benp@npsa.com</a><BR>
Date: Mon, 11 Aug 1997 23:14:37 -0700
</B><p><B>Jim,
</B><p><B>I'm not sure if you are the right person to ask but I figured you
would be a good place to start. I have a handful of PC's that I need
to be able to watch as they boot. What I would like to do is connect
a dumb terminal(old laptop) to a rs-232 switch box and then be able
to switch to any of the machines as I boot them. I was wondering if
you knew any way to do this. Thanks.
</B><p><B> Ben Peikes
</B><P>
<img align=bottom alt=" " src="../gx/ans2.gif">
It is possible to use a serial terminal as a console
for Linux -- given some patches. With some PC hardware
you'll have to leave the video card in their -- though
you don't need a monitor attached.
<p> Unfortunately I don't remember where I saw these patches.
I'd so a search on "+Linux +serial +console" (using the
Yahoo! convention of preceding "required" terms with
"plus" signs).
<p>--
Jim
<!--================================================================-->
<P> <hr> <P>
<center><H4>Previous "Answer Guy" Columns</H4></center>
<P>
<A HREF="../issue13/answer.html">Answer Guy #1, January 1997</A><BR>
<A HREF="../issue14/answer.html">Answer Guy #2, February 1997</A><br>
<A HREF="../issue15/answer.html">Answer Guy #3, March 1997</A><br>
<A HREF="../issue16/answer.html">Answer Guy #4, April 1997</A><br>
<A HREF="../issue17/answer.html">Answer Guy #5, May 1997</A><br>
<A HREF="../issue18/lg_answer18.html">Answer Guy #6, June 1997</A><br>
<A HREF="../issue19/lg_answer19.html">Answer Guy #7, July 1997</A><br>
<A HREF="../issue20/lg_answer20.html">Answer Guy #8, August 1997</A>
<P><HR><P>
<center><H5>Copyright &copy; 1997, James T. Dennis <BR>
Published in Issue 21 of the Linux Gazette September 1997</H5></center>
<P> <hr> <P>
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