The Mailbag

• Linux boots from RAMdisk,
• Python conferences in the US and Europe

Linux boots from RAMdisk,

ASUS P5A-B motherboard with AMD-K6-2 300MHz cpu. Other people report assorted linux boot problems with this board and other ASUS boards.

I can boot my version of linux (Basixlinux 2, based on Slackware 7.1, or Basiclinux 3 with the SW71 kernel but libc5) from a 2-floppy lilo-boot version that uses RAMdisk, a loadlin-boot RAMdisk version, a loop version, or SW4.0 zipslack (UMSDOS). But if I try to boot BL2 or BL3 with loadlin from a hard drive installation, with the kernels compiled for them or with bare.i Slackware kernel, the boot process stops at the lines:

Linux NET4.0 for Linux 2.2
Based upon Swansea...
Net4:  Unix domain sockets 1.0 for Linux NET4.0

(The Basiclinux kernel gets me two lines further along to something about TCP).

I tried starting with FreeDOS, DR-DOS, and Win98 DOS (since I have three other computers that will boot linux with loadlin from Win9X DOS but not always from the others, and one that will boot loop linux from any DOS except Win9X). I do not have a hard drive version set up to boot with lilo. Is that likelier to work? I don't want to use lilo as I work in DOS more of the time.

I tried telling CMOS that there was no second drive because someone suggested that method to get linux to recognize a larger drive, but my drive is 3GB. I have DOS on a master drive and two linux partitions on the slave drive, with one linux in each, and RAMdisk and loop versions in DOS partitions.

I am able to mount the linux partitions when running from the RAMdisk or loop versions and then switch to run linux on them:

mount /dev/hdb1 /mnt
chroot /mnt

This puts hdb1 on / and I can then use linux on the ext2 partition.

[Kapil] But this is essentially what most initrd-based start up procedures do anyway! So, though I haven't used BasixLinux, I would guess that the problem is with the start scripts on your ext2 partition in /etc/rcS.d or some such.

This is a minor nuisance and I suppose I could put it in an rc file, or just use the smaller version unless I needed the larger one.

I am writing out of curiosity - why are so many computers difficult to boot with linux?

[Kapil] The glass could also be half full! Given the variety of hardware that Linux runs on it is surprising that so many computers boot with it at all.

Is there a better fix for this one? Is there a better fix for the other three besides installing Win98 DOS on them (and having to use a boot floppy to defragment the DOS partitions after that) or rebooting with a Win98 boot disk to go from DOS to linux?

I also have one Northgate 386 SX 20MHz 4.7MB RAM laptop which has no cursor in linux. Cirrus video, 256K video RAM, mono VGA. The cursor is plain white when used in color VGA. The computer in theory can output to a color monitor in 800x600 resolution.

[Kapil] Is this with or without X? The question is not clear enough. Are you in graphics mode or text mode?

Does laptop video treat software cursors oddly? A cursor appears when I use a text editor. There is a cursor while booting to DOS and in DOS.

Another 386 with identical speed, RAM and video won't boot linux at all - the screen goes black and I need to reboot. What might cause this problem?

[Kapil] Try booting with the additional option "vesafb=off". Some of the older hardware may not respond well to being switched to graphic mode.

Thanks for your help a couple of years ago getting my first linux set up
to work with both TTL and VGA monitors.

On behalf of The Answer Gang, you're welcome... (/me turns to our Gentle Readers) and anyone among our readership who'd like to jump in on the problem (our header does say "...and You!" after all) is welcome to send replies to you, and encouraged to Cc: tag (The Answer Gang) at linuxgazette.net. -- Heather

Python conferences in the US and Europe

Mike sent this to his local Python user group, and to our Answer Gang. I think it's an interesting question, one all you pythonistas out there might be willing to express an opinion about. Reply to tag@lists.linuxgazette.net; Mike will let his pal know if we get some reasonable statistics, and juicy replies may end up in a future mailbag. -- Heather

I got an interesting call from a friend of mine, a PyCon regular who, as it turns out, lives in Sweden. There's been a discussion on the PyCon list about whether the $175 conference fee is too high, too low, or just right. That got her asking me what would it take to get more Americans to present a talk at EuroPython (in Sweden next July -- http://www.europython.org) and Python UK (in England next April -- http://www.accu.org/conference), and more Europeans to PyCon (in Washington DC next April -- http://pycon.org). I thought I'd throw the question out to y'all for ideas. Not everyone here is interested in Python, but the same thing applies to Linux and other free software projects.

She said that she could guess why why not many American presenters would go to Europe, but she wanted to ask somebody on this side of the pond in case there were factors she wasn't aware of. I said the main problem for Americans (besides the expense) is that most people only get two weeks' vacation per year, so they have to use the time selectively. She asked why that was, since in Sweden the minimum is six weeks and most people get nine. I said I don't know, it's just a longstanding tradition. She asked why people don't demand more. I said people are much more concerned about health care, and more vacation time is lower in their priorities.

She said that for her, the main problem with coming to American conferences is the expense. That seems to be outside our control since the conference fee is minimal already, and we can't do anything about airfares or accommodation fees. 'Course the falling dollar will help.

As far as I can tell, the most important thing is just to keep these conferences going, so that even if people can't attend next year, maybe they can do the year after, or maybe some overseas people will go to one and others to the next.

Another thing that's happening in the Python world is different kinds of events are emerging. These three are traditional conferences with speakers. In Seattle we've had a couple sprints (=weekend hacking sessions) without speakers, and I gather those are happening in Europe too. So maybe the answer is not just more opportunities for speakers, but more types of events.

Any other ideas?

• Re: your comment suggested an article idea
• LG #109 - Laundrette
• Math bug in Advanced Features of netfilter/iptables article

Re: your comment suggested an article idea

Edgar Howell is one of our article authors, see http://linuxgazette.net/authors/howell.html for his bio. -- Heather

As you noticed, the use of a wildcard in a command like mount really blew me away. The remark you added to my article compounded it. find, great. less, OK... mount?!

[Ben] [grin] Yeah, pretty amazing. It gets much more amazing when you install and enable "bash_completion"; all the... well, stuff that has multiple options becomes available at the prompt. E.g., typing "ssh " (note the space) and hitting 'Tab' twice shows me a list of all the hosts in my ~/.ssh/known_hosts; typing "mount " and hitting 'Tab' three times (since all the entries start with '/', which is displayed immediately) gives me a list of all the directories listed in "/etc/fstab"... obviously, completion happens when you have a unique string: I've been doing "ssh li<Tab><Enter>" for a session at linuxgazette.net for so long that I'd be lost without it.

If you count the couple of years I had used Coherent prior to graduating to SuSE Linux, I've probably been at *nix for 10 years or so. In other words off the steep part of the learning curve, but, boy, is there ever enough curve left!

[Ben] That's the lovely thing about Unix, to me. You keep gaining these chunks of power every time you learn something - and the chunks don't get any smaller with time. It can be a little tough on the ego for the folks who think that way... but to me, it's a fantastic opportunity to squeeze any amount of juice that I may need out of a system. It's not a question of "is it possible" any longer, but "where do I find the HOWTO?" instead.

Anyhoo, I would like to encourage you to do an article on obscure uses of wildcards on the command line.

[Ben] Um. Well... the problem is in defining "obscure". To me, they're not; they're just how shells operate. To someone else, they may well be obscure. Say... maybe looking at it in broader terms would be useful - an article, or even a series on CLI usage in general might be pretty good!

I'm sorta swamped for the moment - and actually "owe" about three articles to myself - but that one sounds like a really good idea.

Like ignoring the consequences of SuSE's apparent elimination of the need for mount -- there are still questions in my mind but, then, I bounce back and forth between root and any of several users a lot and may have messed things up -- what would "mount *" do?

[Ben] It would give you an error.

Try to mount every /dev? Cycle through /etc/fstab? root can mount stuff not in /etc/fstab. Permissions. Users. Mind-boggling.

[Ben] Essentially, you've answered your own question: "mount *" would just be too ambiguous. E.g., "ssh " or "ssh ben@" is not at all ambiguous: the host name is what has to come after either one of them, and it makes sense that hitting the completion key (Tab) would "complete" them or show the possible options. I assume you know that 'Tab' works to complete program names at the CLI, right? Filenames, too - "vi ~/.bash_p<Tab>" pulls up my "~/.bash_profile" every time.

Keep up the good work

[Ben] Thanks, Edgar! Heck, you might want to write the article yourself: read the Bash man page, and take a look at the "/etc/bash_completion" script. That should give you a good start.

LG #109 - Laundrette

I had just settled in of a Saturday evening with a wee dram of Irish whiskey, a good Henry Clay cigar and Linux Gazette #109. I had worked my way to "Return of the Linux Laundrette" and reached the section "Re: [LG 87] help wanted #4". This piece caused me to drop my cigar (due to uncontrollable grinning, giggling and guffawing), setting my sweatpants on fire.

http://linuxgazette.net/109/lg_laundrette3.html#nottag2/14 for the terminally lazy

I'm fine, thanks - I extinguished the blaze by spilling my libation in my lap - followed, of course, by the water chaser. Be advised that I will be taking legal advice re: financial recovery for the loss of the whiskey...

Well, Ben and I have our own sideline business (http://linuxgazette.net/107/misc/laundrette/lg_hitsquad.html), so I can say with some confidence that it won't come to that, though some recovery may occur at some later date.

I don't know how you people manage to produce such an outstanding combination of useful Linux information, non sequiturs and a, ah, rather <veering> approach to humor (my kind!) - but I certainly hope you keep doing it for a long time to come.

Well, I'll be compiling it for a while to come: it's a lot of fun to go back over the offtopic threads every month, especially since there are so many of them --

Dec 01 08:44:05 <editorgal>     lucky sucker, the recent gang must be a treasure trove for laundrette bits.
Dec 01 08:45:29 <jimregan>      I felt kind of duty bound to take over the laundrette... 
cos most of the time all I do is perpetuate those threads 
[though I should have said 'perpetrate' :) ]
Dec 01 08:45:39 <editorgal>     lol

Sincerely,
Mark W. Tomlinson

Thanks for writing,
Jimmy

Math bug in Advanced Features of netfilter/iptables article

Hi Rich, all,

Advanced Features of netfilter/iptables by Barry O'Donovan [November 2004 (#10 ] was a very informative article.

Thanks! It's always good to hear positive feedback.

But my "math flag" flew from my pocket when I saw his example for using the random module.

So did mine on reading the published article. I had actually planned to point it out with an Octave example demonstrating the difference between the right and wrong answer in this months article, but when it came to writing it I discarded the example as it didn't fit with my layout and completely forgot to add it as erratum.

If there is one thing I have learnt about statistics (and I've learnt quite a lot between my degree which was top heavy on stats and my research where I use the damn stuff every day) is that if the answer is simple, then it's just plain wrong!

If you wish to divide the packets evenly among the four servers then the example should look like this:

-A PREROUTING -i eth0 -p tcp --dport 80 -m state --state NEW -m random --average 25 \ -j DNAT --to-destination 192.168.0.5:80
-A PREROUTING -i eth0 -p tcp --dport 80 -m state --state NEW -m random --average 33 \ -j DNAT --to-destination 192.168.0.6:80
-A PREROUTING -i eth0 -p tcp --dport 80 -m state --state NEW -m random --average 50 \ -j DNAT --to-destination 192.168.0.7:80
-A PREROUTING -i eth0 -p tcp --dport 80 -m state --state NEW -j DNAT --to-destination 192.168.0.8:80

The reason is that, after 25% of the packets are NATed by the first rule, only 75% of them will be seen by the second rule. A third of them would equal 25% of the total. Likewise, the third rule will see only half of the total and half of that is 25% of the total.

Correct. A subtle and simple mistake that might cause many a sys-admin a prolonged headache!

When speaking of mistakes and statistics, I'm always reminded of a few quotes:

............... "There are two kinds of statistics: the kind you look up and the kind you make up." "I gather, young man, that you wish to be a Member of Parliament. The first lesson that you must learn is, when I call for statistics about the rate of infant mortality, what I want is proof that fewer babies died when I was Prime Minister than when anyone else was Prime Minister. That is a political statistic." "You know how dumb the average guy is? Well, by definition, half of them are even dumber than that." "Statistics in the hands of an engineer are like a lamppost to a drunk-they're used more for support than illumination." "Numbers are like people; torture them enough and they'll tell you anything." "There are three kinds of lies: lies, damn lies, and statistics." "A statistician is a man who comes to the rescue of figures that cannot lie for themselves." "First get your facts; then you can distort them at your leisure." ...............

Ahhhh.... statistics. So easy to love and hate all at once!

Cheers, Barry

P.S. Thanks also to John Macdonald and one of our French translators, Emmanuel Araman, who also pointed this out to me.

• Linux Gazette: checking in from India

Re: Linux Gazette: checking in

I hadn't sent this to TAG - it was a semi-private query - but, for general info, I was checking in with all our Indian correspondents:

• http://linuxgazette.net/authors/mathew.html
• http://linuxgazette.net/authors/sunil.html
• http://linuxgazette.net/authors/kapil.html
• http://linuxgazette.net/authors/shuveb.html
• http://linuxgazette.net/authors/pramode.html
• http://linuxgazette.net/authors/sayamindu.html
• http://linuxgazette.net/authors/shekhar.html
• http://linuxgazette.net/authors/ramankutty.html
• http://linuxgazette.net/authors/krishnakumar.html
• http://linuxgazette.net/authors/ashwin.html
• http://linuxgazette.net/authors/rajith.html

• http://linuxgazette.net/authors/pai.html
• http://linuxgazette.net/authors/raghu.html

I sent the message out last night; so far, the first five people have responded. My best hopes and wishes go out to the rest, and to all.

[Breen] Thanks for that, Ben. Please let us know as you hear from more of our Indian friends.

I surely will, Breen. So far, we've got Vinayak's name to the five who had responded previously; Sayamindu Dasgupta's address bounced, but I found a phone number for him at http://peacefulaction.org which he listed in his author profile. He's OK; seems he's in Kolkata (West Bengal), and everything is all right there.

Folks, please keep them on your good wishes list or in your prayers, as appropriate. It may be a small thing in the face of something this huge, but... it's something. As Pramode said, "there are still human beings alive who can feel the sorrow in another person's eyes - that's the only consolation."

[Ben] Are you all OK? I'd appreciate a response if you get a chance. I'd imagine that many others here are just as concerned; I think that a lot of people may just be... too stunned by the magnitude of this to come up with a coherent response, and unsure of their own degree of connection to you all. Me, I figure that we're all human beings - and that no man is an island.

My heart goes out to you and all your countrymen in this difficult, terrible time.

[Kapil] Thanks for checking. Yes. It is truly a devastating event here. Relief agencies are doing what they can but every bit counts.

I'm going to be letting people around here (northern Florida) know that they can contribute to the Red Cross/Crescent India, and am going to send a contribution myself. [sigh] Sunil mentioned that there's now another warning out.

[Kapil] The strange aspect of the tragedy is that people in Chennai who were more than about 500 metres from the coast were almost unaware that anything had happened. Since we live somewhat inland we were quite unaffected.

[Nod] Tsunamis are like that. They're slow and quiet, definitely so at first; the traditional way to commit suicide during one is to follow the ocean as it recedes from the shore.

Folks - everyone - imprint this in your brain forever: if you ever see the ocean receding, RUN like hell for the high ground. You at least stand a chance of surviving, then.

[Kapil] P.S. There is no word for "tsunami" in any of the local languages which perhaps gives an idea of how unexpected the event was.

[Vinayak Hegde] You can add me to the list.

With great pleasure! I just went through our list of authors, and emailed everyone that was in India; you're just not listed as an author, so no contact info came up. Glad to hear you're OK, too!

[Vinayak Hegde] Thanks. Actually I am listed as a author . http://linuxgazette.net/authors/vinayak.html

[blink] Then I simply missed you. Ooops.

[Vinayak Hegde] I live far away from the coast (in Bangalore). We did mobilise help and have donated a lot of clothes/medicines for relief work. Though we are safe in center of the Indian peninsula, we were shocked by the images that were shown on television and splashed on the front pages of the newspapers. I also read that 5 endangered tribes living in the Andaman and Nicobar islands were wiped out forever and a few islands were washed away (literally).

[sigh] Damn. The only thing I'd ever heard about Andaman islanders was the fanciful stuff from Conan Doyle... and now, they're gone. Forever.

Contention from various quarters notwithstanding, this world is not particularly friendly to man. I realize that it does no good to rail against the weather, but... blood and hell, man! This is just appalling.

[Vinayak Hegde] Yeah. It's good to know that I am not the only Sherlock Holmes Fan on this List The Andamani Pymgy had a major role to play in "The Sign of Four". Who could forget the thrilling story??

Link to the "Times of India" article here:

http://www.freerepublic.com/focus/f-news/1309884/posts

Oh, indeed. And what a picture he draws! Reminded me quite a lot of Jack London's "South Sea Tales", or perhaps "Adventure", and his descriptions of the Salomon islanders.

Any news about the latest warning that Sunil mentioned?

[Raj Shekar] Thanks a lot for writing. I am in Delhi, which was quite far from where the tsunami stuck. I will be making a donation to the Prime minister's fund and also write in to the local LUG to see if we can do more than just sitting. One of the members of the mailing list is working with the people who have been hit and has written down the things they need:
https://ssl.cpsr.org/pipermail/india-gii/2004-December/009559.html

1. Children's clothes in decent form
2. Medicines - Paracetamol, ORS packets, Doxycycline, Dettol, bandages
3. Blankets - a few thousands
4. Gloves & masks to help volunteers clear the debris & dead bodies.
5. Money - to buy essentials, water pots (which will be bought closer to the areas)

Editor's note: Paracetomol is known as Acetominophen in the US, and might be under that name in other countries. -- Heather

I hope I will be able to find some (honest) agency who will be willing to take donations of medicine and blankets.

Thanks again for caring

[Jimmy] Wikipedia have an international list: http://en.wikipedia.org/wiki/Donations_for_victims_of_the_2004_Indian_Ocean_earthquake

[Hiran Ramankutty] I am absolutely fine. By god's grace I am not near the vicinity of the Tsunami. But hearing about the disaster itself gives enough sight of what would have happened.

Pray for all Tsunami victims.

[Krishnakumar R] I am fine. I had come home (Kerala in southern India) for a 10-day holiday. But as my native place is far from coastal area, I was not affected.

I can also vouch for Pramode. C . E , that he is safe, as I had met him in person day-before-yesterday.

Ben, I really appreciate the concern and the kindness you extend to all of us. Thank you very much.

It is during the dark times like this that we understand how precious our lives are; which we usually take for granted. Lets all extend our help in whatever way we can, to the victims of this tragedy.

[Ashwin N] I am fine. I stay in Bangalore which is very far from the coast.

This truly has turned into a catastrophe of immense proportion. Entire fishing communities have been washed away in some places

Rajith is OK; by extension, Maxin B. John (whom I missed due to the name...) must be OK as well - they co-authored an article last month, so I figure they're in close touch.

[Rajith R] Thanks for checking in. I am ok and I live in Trivandrum. Even tough it is near sea here there were no problems.

As of press time there our very few of our Indian authors and TAG members who have not checked in - Raghu J Menon, and Krishna G Pai. Raghu lives in Kerala, and somehow it seems like everyone knows Pramode (hey Pramode, check in on 'em will ya? Thanks buddy). If you have news of our friends, please let us know.

May this New Year be better than our last, and whatever troubles we suffer draw us closer rather than tear us apart. With love to you all -- Heather