Linux-Misc Digest #669, Volume #27 Sat, 21 Apr 01 13:13:03 EDT
Contents:
Re: Could Linux be used in this factory environment ? (Charles Lyttle)
Re: Could Linux be used in this factory environment ? (Charles Lyttle)
Balsa wont send (Rick)
netbooting tagged kernel gives screen junk and error message (Jeroen Kransen)
where did xinitd come from? (Dave Brown)
Re: help. programs segfaulting. (Dave Brown)
Re: alien-7.22-1mdk.i586.rpm (Dave Brown)
Re: multiple instances of dameons and other processes? (Dave Brown)
Re: Question about Strange Report of Disk Space,thanks. (Dave Brown)
Re: tty7,8,...? (Dave Brown)
Re: Qt Designer (FUNG WAI KEUNG)
Re: where did xinitd come from? (Robert Lynch)
Re: Reliability of "time" command? (MH)
Re: LILO version 21.7.3 released (John in SD)
Re: lost LILO (John in SD)
Re: Reliability of "time" command? (MH)
Re: RAID 5 or 0 for performance? ("Ron Reaugh")
----------------------------------------------------------------------------
From: Charles Lyttle <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.advocacy,comp.os.linux.hardware
Subject: Re: Could Linux be used in this factory environment ?
Date: Sat, 21 Apr 2001 14:16:13 GMT
Monte Milanuk wrote:
>
> Charles Lyttle <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]...
> > > Man..that ladder logic is the wierdest way to program I've ever seen.
> > If you have never used it, it would seem strange. But just think, there
> > was automatic code generation before PCs. You can draw a diagram on your
> > display, and it starts running. The VM reads a line of the drawing and
> > executes it. Sort of like having a VM read a UML diagram and run the
> > code.
>
> As an ex-motor control electrician in a large steel mill, I have to agree.
> Ladder logic makes a lot of sense if you are trained in how to troubleshoot
> using electrical prints. Plus, the dirty little secret of PLC's and ladder
> logic programming as far as I'm concered is that it is dirt easy to bypass
> and circumvent failed field devices. No physical rewiring required. W/ a
> PLC and ladder logic, it's pretty easy to figure out where you need to
> modify things, and how. But to do the same w/ a regular programming
> language... maybe for a professional programmer it might be simple, but not
> for most technicians, I think. Not that tech's are stupid, just it's not a
> normal way of thinking for them. That, and most people that proficient at
> programming seem rather adverse to getting dirty on a regular basis ;p
>
> Monte
A good project for Linux open source would be a ladder logic
development/run-time enviornment. It should have provisions for
constructing and printing ladder diagrams. It should have a runtime
enviornment that intreprets the diagram routing signals to/from the
external hardware. For emergency situations, it should have provisions
for over-riding the state of objects (password required).
--
Russ Lyttle
"World Domination through Penguin Power"
The Universal Automotive Testset Project at
<http://home.earthlink.net/~lyttlec>
------------------------------
From: Charles Lyttle <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.advocacy,comp.os.linux.hardware
Subject: Re: Could Linux be used in this factory environment ?
Date: Sat, 21 Apr 2001 14:30:09 GMT
Erik Funkenbusch wrote:
>
> "Charles Lyttle" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]...
> > Mind you, I can't vouch for the accuracy of that report. But is was
> > offered as proof that the crash wasn't the fault of the OS. "It was a
> > misbehaving application that caused the OS to crash." The Navy had to
> > clear the OS or justify to congress why it insisted on MS when most
> > contractors were saying it couldn't (or shouldn't) be done. The
> > contractor had to clear the OS because he promised that it could be
> > done. But he was late, and the Navy had to either cancel a test at a
> > loss of millions, or go to test with a beta version. So the vendor says
> > "we were only a little late, if they had just waited a few more days".
>
> This is all completely untrue.
>
> Read all the info collected by Jerry Pournelle on the issue
> http://www.jerrypournelle.com/reports/jerryp/Yorktown.html
>
> The contractor in question also stated specifically that the navy had gone
> against their recomendation of installing newer software that didn't have
> the problem PRIOR to the event.
> http://www.sciam.com/1998/1198issue/1198techbus2.html
>
> "... the fault was with certain applications that were developed by CAE
> Electronics in Leesburg, Va. As Harvey McKelvey, former director of navy
> programs for CAE, admits, "If you want to put a stick in anybody's eye, it
> should be in ours." But McKelvey adds that the crash would not have happened
> if the navy had been using a production version of the CAE software, which
> he asserts has safeguards to prevent the type of failure that occurred. "
>
> You should also read the original article which is the source of all this:
> http://www.usni.org/Proceedings/digiorgio.htm
>
> Notice that in an article of great length, only 2 paragraphs are devoted to
> NT, and none of the say the OS crashed.
>
> Further, the same author that wrote the gcn article (which quotes from the
> usni article) also clarifies his statements in a followup article:
> http://www.gcn.com/archives/gcn/1998/november9/6.htm
That last one is even worse than my story. A divide by zero in the
controller for a fuel valve caused the entire LAN to go down crashing 27
remotes? Industry (mostly) fixed that problem 30 years ago. For what its
worth, I had an NT machine I was working with bring down an entire LAN
of over 1000 machines. It was called the "ping of death". Some
applications could cause the NT software to start issuing network pings
at high speed. These faults often also caused a BSOD, but not always.
--
Russ Lyttle
"World Domination through Penguin Power"
The Universal Automotive Testset Project at
<http://home.earthlink.net/~lyttlec>
------------------------------
From: Rick <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.powerpc
Subject: Balsa wont send
Date: Sat, 21 Apr 2001 10:47:41 -0400
I cant seem to send mail with Balsa. At least I cant send it to my self.
I address an email to myself and send it. It doesnt show up on my ISP's
mail server. I can receive mail Or, I think I can. Balsa wants to DL
something like 300+ messages.
Any and all help appreciated.
--
Rick
------------------------------
From: Jeroen Kransen <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.networking,comp.os.linux.embedded
Subject: netbooting tagged kernel gives screen junk and error message
Date: Sat, 21 Apr 2001 16:01:57 GMT
Hello, I tagged a kernel with mknbi-linux, and when I boot the client,=20
ist finds the file and starts loading it, but during the loading I see=20
all this binary junk roll over my screen and then it says that the=20
file is too large for the lower memory or something. This doesn't seem=20
likely, since the kernel is only 570k and I don't see get it smaller=20
anyway. I created the root filesystem in /tftpboot with the script in=20
the Diskless-HOWTO.=20
jeroen
------------------------------
From: [EMAIL PROTECTED] (Dave Brown)
Subject: where did xinitd come from?
Reply-To: [EMAIL PROTECTED]
Date: 20 Apr 2001 14:41:03 -0500
I've been (forced into) playing with RH 7.0, and after trying to
telnet into the box from a machine with more comfortable chair, I
discovered that RH no longer installs a telnet daemon by default.
Not realizing that, I went looking for inetd.conf and found it missing.
Apparently xinetd is now the going thing. (...obsoleting all the
references out with regard to networking administration.)
So, I'm wondering where xinetd came from, what was the motivation
for going to it, is tcpd still in use? ...etc. Is there a write-up
somewhere that would lay it out for me, so I wouldn't think this is
just another "change for the sake of change".
--
Dave Brown Austin, TX
------------------------------
From: [EMAIL PROTECTED] (Dave Brown)
Crossposted-To: comp.os.linux.admin,comp.os.linux.help
Subject: Re: help. programs segfaulting.
Reply-To: [EMAIL PROTECTED]
Date: 20 Apr 2001 22:21:30 -0500
In article <87g0f3i0wl.fsf@localhost>, [EMAIL PROTECTED] wrote:
>i'm using slackware 7.1. i'm having a problem with programs
>"sometimes" segfaulting. take vi for instance. i cant run "vi" from
>the command line because it segfaults. but i can run "gvim" from X
>windows. and if i run "gvim" from the command line while not in X, it
>gives me the usual "Cant open Display" error but then it loads the
>console version of vi without any problems. so i can use gvim, but not
>vi.
>
>something similar happens with netscape. i used it a little while ago
>and it worked just fine. now when i try to start it up, it gives me a
>"Bus Error". But if i reboot, it works fine again.
>
>I sometimes have similar problems with emacs. first it works, then it
>starts segfaulting on startup for no apparent reason, and then it
>works just fine again. I dont know when the segfaulting is going to
>start, or when it's going to end or why.
Sounds like a hardware problem to me... probably a bad memory module,
or perhaps mismatched memory modules. If you have more than one module,
you might try removing one, then the other, and see if things settle down.
--
Dave Brown Austin, TX
------------------------------
From: [EMAIL PROTECTED] (Dave Brown)
Subject: Re: alien-7.22-1mdk.i586.rpm
Reply-To: [EMAIL PROTECTED]
Date: 21 Apr 2001 00:50:55 -0500
In article <O77E6.2721$[EMAIL PROTECTED]>,
Missy wrote:
>I've tried installing this over and over. It looks like it installs, but
>when I type in the program name to run it, it says that it cannot find the
>file. What do I do? I was hoping to use it to install source codes. If
>anyone has any info on installing source codes too, that would be
>appreciated.
Find out where it installed. (rpm -qlp alien* | grep alien) It has
probably put the executable in some directory that is not on your search
path. (Did you install into Mandrake or some other distro?)
--
Dave Brown Austin, TX
------------------------------
From: [EMAIL PROTECTED] (Dave Brown)
Subject: Re: multiple instances of dameons and other processes?
Reply-To: [EMAIL PROTECTED]
Date: 21 Apr 2001 01:03:36 -0500
In article <9bqqcd$hlg$[EMAIL PROTECTED]>,
[EMAIL PROTECTED] wrote:
>#1 Is there some sort of deamon manager that i can use to stop
>unwanted deamons from running, or perhaps something that i can make
>things like lpd (or cardmgr) come up only when needed (deamon on demand?)
>
>#2 i have little idea of what things i am able to do with out (or
>don't need to run more than once), how essential are the things
>i have "*" beside and how might i go about unloading them?
>
>#3 i see something that look like they are running more than once,
>is there something i am missing here?
>
> PID TTY TIME CMD
>* 339 ? 00:00:00 nscd
>...
>* 388 ? 00:00:00 httpd
>...
>* 410 tty3 00:00:00 mingetty
>...
Actually, I can't tell you what nscd, 'cause I don't have it, and have'nt
seen it before. httpd is probably apache. mingetty creates a "virtual
terminal" Often a master daemon spawns "spare" daemons to handle multiple
requests for the same service from different requestors. (httpd, for example,
in case you get multiple http requests "at the same time".
But fear not, a daemon which is just listening is probably not consuming
many cpu cycles. Likewise, multiple instances of the same executable do
not occupy the full memory space of the first instance, 'cause it is
re-entrant code, so only one copy of the code is in memory at once.
But usually, daemons which spawn spares can be configured to set the number of
spares to create. Check the configuration file.
--
Dave Brown Austin, TX
------------------------------
From: [EMAIL PROTECTED] (Dave Brown)
Subject: Re: Question about Strange Report of Disk Space,thanks.
Reply-To: [EMAIL PROTECTED]
Date: 21 Apr 2001 01:06:52 -0500
In article <Dw1E6.198143$[EMAIL PROTECTED]>, harrison wrote:
>Hi, there:
>
>Filesystem Size Used Avail Use% Mounted on
>/dev/sda1 1.2G 551M 571M 49% /
>
>/dev/sda6 4.7G 4.4G 0 100% /home
>
>/dev/sda7 1.2G 106M 1015M 9% /var
>
>I dont know why available space on /home is 0, it should be 300M left ,
>right ?
Don't forget that file systems reserve space to be used by root only.
The % reserve value is usually 3-5%. It can be seen with:
dumpe2fs /dev/sda6
and can be modified with tune2fs.
--
Dave Brown Austin, TX
------------------------------
From: [EMAIL PROTECTED] (Dave Brown)
Subject: Re: tty7,8,...?
Reply-To: [EMAIL PROTECTED]
Date: 20 Apr 2001 14:19:59 -0500
In article <[EMAIL PROTECTED]>, Hartmann Schaffer wrote:
>In article <[EMAIL PROTECTED]>, Jeffrey J. Bacon wrote:
>>so if I just copy those lines in the /etc/inittab file (changing thier
>>id to 7,8,..) and open getty on tty7,8,9... then I'll get those virtual
>>terminals?
>
>you'll get at least terminal 7 (and lose X). i'm not sure, but to go
>beyond 7 you might have to change some configuration parameter
Did you try this out before rendering your answer? You do not "lose X".
If you added 2 virtual terminals, 7 and 8, then X would show up on
"screen 9" (alt-F9). I would guess if you assigned all 12 screens, that
X might have a problem, but I don't know that.
On the other hand, if one is running X, what on earth do he need all those
virtual terminals for?
--
Dave Brown Austin, TX
------------------------------
From: FUNG WAI KEUNG <[EMAIL PROTECTED]>
Subject: Re: Qt Designer
Date: 21 Apr 2001 15:24:07 GMT
Hi, Designer is included in standard Qt library. You just need to
download the tarball of Qt from trolltech and you will have designer in
it.
[EMAIL PROTECTED] wrote:
: Hello there,
: Any one can point me to a site that I can download QtDesigner. I look all
: over Trolltech.org. Found it but did not lead me to down load directory.
: Thanks,
: Myint
: --
: Posted via CNET Help.com
: http://www.help.com/
--
Regards,
Wai Keung, Fung
Department of Automation and Computer-Aided Engineering,
The Chinese University of Hong Kong,
Shatin, N.T.,
Hong Kong
Tel: (852)26098056 Fax: (852)26036002
Email: [EMAIL PROTECTED]
------------------------------
From: Robert Lynch <[EMAIL PROTECTED]>
Reply-To: [EMAIL PROTECTED]
Subject: Re: where did xinitd come from?
Date: Sat, 21 Apr 2001 08:51:18 -0700
Dave Brown wrote:
>
> I've been (forced into) playing with RH 7.0, and after trying to
> telnet into the box from a machine with more comfortable chair, I
> discovered that RH no longer installs a telnet daemon by default.
> Not realizing that, I went looking for inetd.conf and found it missing.
> Apparently xinetd is now the going thing. (...obsoleting all the
> references out with regard to networking administration.)
>
> So, I'm wondering where xinetd came from, what was the motivation
> for going to it, is tcpd still in use? ...etc. Is there a write-up
> somewhere that would lay it out for me, so I wouldn't think this is
> just another "change for the sake of change".
>
> --
> Dave Brown Austin, TX
It's for increased security. You can, and RH7 does, compile in
tcpd protection. IMO a pretty good article is at Linuxfocus:
http://www.linuxfocus.org/English/November2000/article175.shtml
HTH. Bob L.
--
Robert Lynch Berkeley CA USA [EMAIL PROTECTED]
------------------------------
From: MH <[EMAIL PROTECTED]>
Subject: Re: Reliability of "time" command?
Date: Sat, 21 Apr 2001 09:00:41 -0700
Francis Litterio wrote:
>
> MH, how much data is being transferred between these disks and just how
> long does it take (according to the "time" command)?
>
As a comparison, I ran "time" on the "du" command for each system, thus:
time du -s /
For the larger data source (~7 GB) "du" reported 8.95s
For the smaller data source (~2.5 GB) "du" reported 4.63s
--
I use GNU/Linux and support the Free Software Foundation. This message was
composed and transmitted using free software, licensed under the General
Public License.
--
------------------------------
From: John in SD <[EMAIL PROTECTED]>
Subject: Re: LILO version 21.7.3 released
Reply-To: [EMAIL PROTECTED]
Date: Sat, 21 Apr 2001 16:10:15 GMT
On Tue, 3 Apr 2001 22:53:05 +0100, Andy Collinson <[EMAIL PROTECTED]>
wrote:
>I tried Lilo 21.6 but could only dual boot from a floppy disk; my problem
>is my hard drive is hde and higher than the 1024 cylinder limit. Lilo can
>cope with the cylinder but the error message was only hda only. Can 21.7
>cope with hard drive on the 3rd IDE connector?
All versions of LILO can cope with drives on the 2nd, 3rd ... IDE controllers.
But you must explicitly specify how the bios has assigned device codes:
disk=/dev/hda bios=0x80
disk=/dev/hdb bios=0x81
disk=/dev/hdc bios=0x82
...
The first two above are usually not needed. But beyond /dev/hdb, you will
probably need a disk/bios assignment.
This is especially true on mixed IDE/SCSI systems, too.
--John
LILO version 21.7 (24-Feb-2001) source at
http://www.ibiblio.org/pub/Linux/system/boot/lilo
patches to -2 at ftp://brun.dyndns.org/pub/linux/lilo
------------------------------
From: John in SD <[EMAIL PROTECTED]>
Subject: Re: lost LILO
Reply-To: [EMAIL PROTECTED]
Date: Sat, 21 Apr 2001 16:16:19 GMT
You'll have to re-boot the Linux partition from a floppy disk, or CD.
Presumably /etc/lilo.conf is already set up to install a Win/Linux dual boot.
Just re-run /sbin/lilo to re-install the boot loader (on /dev/hda, I presume).
--John
On Sat, 14 Apr 2001 20:57:13 -0400, "Thomas Baker" <[EMAIL PROTECTED]> wrote:
>Can anyone help me restore Lilo. (I duel boot and Win on 1st hard drive and
>Linux on 2nd) I had to reload Windows and it overwrote my MBR
>
LILO version 21.7 (24-Feb-2001) source at
http://www.ibiblio.org/pub/Linux/system/boot/lilo
patches to -2 at ftp://brun.dyndns.org/pub/linux/lilo
------------------------------
From: MH <[EMAIL PROTECTED]>
Subject: Re: Reliability of "time" command?
Date: Sat, 21 Apr 2001 09:17:23 -0700
Garglemonster wrote:
> rudeness and vulgarity can be fun and cathartic, but civility works
> better in some situations. why this verbal firestorm instead of
> "thanks, but could you explain to me what all this has to do with the
> strange results i get with the time command?"
>
> as for the content of mr. bacon's message, considering that your
> original message posed cpu clock ratings as the only variable, it
> doesn't seem at all unreasonable for someone to respond to you as
> mr. bacon did. he seems quite literate to me. you can hardly expect
> more if you don't provide more detailed information. what does your
> script look like? what is getting copied? how much of it is there?
> are there any hardware differences aside from cpu clock speed?
>
Your post is a PERFECT example of why I went ballistic on Mr. Bacon. You,
too, failed to READ the original post. CPU info was included merely to
avoid having to respond for the inevitable request for CPU speed--in spite
of the fact that it is LARGELY irrelevant in this case. The KEY piece of
information was stated quite clearly in the last sentence of the first
paragraph. It was even followed with muliple exclamation points to provide
EMPHASIS. I quote:
"Furthermore, the box with the slower CPU is transferring nearly 3 times as
much data!!! "
Nevertheless, not only did the first respondent focus on the CPU
data--which was largely irrelevant, as he noted--but he made NO attempt to
explain the anomaly which was the POINT of my post. In fact ONLY ONE
RESPONDENT ACTUALLY NOTED THE DIFFERENCE IN DATA VOLUMES BEING TRANSFERRED.
In short, READ the goddamn post before responding.
--
I use GNU/Linux and support the Free Software Foundation. This message was
composed and transmitted using free software, licensed under the General
Public License.
--
------------------------------
From: "Ron Reaugh" <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.hardware,comp.periphs.scsi
Subject: Re: RAID 5 or 0 for performance?
Date: Sat, 21 Apr 2001 16:16:51 GMT
Dan Smith wrote in message ...
>I have 5 40MB/s SCSI drives (4GB each). I want maximum performance,
>and am not worried about redundancy. Should I use RAID 5 or 0?
RAID 0 with spindle sync emabled.
> I'd
>rather not lose the extra 4GB to RAID 5, but if it would be faster or
>better, then I'd do it.
>
>Using software raid under linux 2.2.
------------------------------
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End of Linux-Misc Digest
******************************
