New USB wireless adapters

January 23, 2011 at 3:35 pm (Linux, Ubuntu, Uncategorized) (, )

I just bought two new wireless network adapters from NCIX. Beforehand, I did a little search to see if they worked at all on Linux, and the information was quite confusing. I splurged, and passed my order anyway. Now that I received them, and for the benefit of the intartube at large, here’s my report.

Trendnet TEW-424UB USB: work perfectly on Ubuntu 10.04, no fussing around.

TP-Link TL-WN722NC high-gain USB b/g/n: Does not work on Ubuntu 10.04 (not recognized). Works out-of-the-box) in Ubuntu 10.10. It has an Atheros chipset. From my investigation, it seems it started being supported in kernel 2.6.35. Amusingly, iwconfig reports it connect at 1 Mbps, but testing with dslreports.com speed test tells me I saturate my DSL link. Go figure, must be a bug!

Because I bought these on NCIX, I wanted to comment on the product description that they do work on Ubuntu, but the NCIX web site would not, saying that my review was too short. Silly. Their loss.

Update: seems like the TL-WN722NC needs the ath9k_htc module. In lucid, you can get it by installing the linux-backports-modules-wireless-compat-2.6.36-lucid-generic package. Pffft!

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expand-ldif

March 25, 2010 at 9:34 pm (English, Linux) ()


#!/bin/sh

# Etienne Goyer <etienne.goyer@xxxxxx.com>,
# (but really Marc Tardif; credits where due)
# March 25th 2010

# The LDIF format have this annoying feature that line continue
# if the next one start with a space. Bleh. That makes the work
# of standard Unix command-line text filter terribly complicated,
# and make parsing the output of ldapsearch very unreliable.
# Piping the LDIF through this first should fix it.

awk '/^ / { l=l substr($0, 2); next }; { print l; l=$0 }; END { print l }'

# Yep, that's it!

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I want to send money to Microsoft. I really do!

October 30, 2009 at 7:05 pm (Consumer affairs, English, Linux, Ubuntu)

That does not happen very often, but I want to buy something from Microsoft. In fact, I really, honestly, do. Namely, a Technet subscription that I need to test some Windows/Ubuntu interoperability stuff I am working on these days.

Unfortunately, it seems Microsoft really isn’t interested in my money at all. I guess they have enough already. Otherwise, why would they purposefully break their online order form for non-IE user?

Technet order form is borked

You know what they say: do not attribute to malice what can be explained by incompetence. But I mean, really, it has been years since I had to deal with stupid rendering issue on non-IE browsers. Only at Microsoft, I guess :(

Let’s see how well IEs4Linux works …

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Interview à propos de Canonical sur CKIA

October 29, 2009 at 3:47 pm (Francais, Linux, Logiciel Libre, Ubuntu) (, , , , , , , , )

J’ai été invité à participer à l’émission de radio La voix du libre sur CKIA 88,3 à Québec, animé par mes amis, le très radio-canadien Yannick Pavard et le très vert François Bédard. L’émission porte sur Ubuntu, en l’honneur du lancement de la version 9.10 qui a lieu aujourd’hui. Mon interview porte plus spécifiquement sur Canonical, l’entreprise derrière Ubuntu, qui se trouve à être mon employeur.

http://www.lavoixdulibre.info/emissions/detail/emission/emission-du-28-octobre-2009-1/4/liste/2009/octobre.html

Je doit saluer, en particulier, la qualité des choix musicaux de l’émission. Si j’ai bien compris, il s’agit de musique libre (CC et cie) trouvé sur Jamendo. En particulier, je suis fou de la pièce Scarecrow Blues de Blind John O’Gunn, un blues suave et authentique.

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/dev/… is apparently in use by the system; will not make a filesystem here!

September 15, 2009 at 6:42 pm (Linux)

Sometime, I end up with these tiny nuggets of knowledge that I know for a fact I will forget shortly. Moreover, when a Google search turn out to confirm that this nugget of knowledge is not part of the collective hive mind yet, I know for a fact I need to do something about it. I could keep it in a flat file or some sort of personal database or brainmap somewhere on my machine, but then I will certainly lose it. I am messy like that. However, if I post it on the intarweb, Google will eventually index it, which mean that next time I Google the problem in question, I will surely stumble upon my own long-forgotten blog post. Call that “netsourcing memory”!

So, while playing around a bunch of HP servers today, swapping drives around and making new logical ones, I stumbled upon that problem:


cloudmaster@uec-frontend:~$ sudo mkfs.ext4 /dev/cciss/c0d2p1
/dev/cciss/c0d2p1 is apparently in use by the system; will not make a filesystem here!

I tried with -FF (“Do as I say, you stupid!”), but it would still refuse to obtemperate. Confirmed with mount and fuser that the partition was not in use, and indeed it was not. Check dmesg, but there was nothing in there.

Turned out there was a logical volume on that drive, and it did not get wiped out in the disk swap. If the same happen to you, you can check that the partition is indeed an LVM physical volume with the command “pvdisplay”. You will then be able to proceed to wipe the LVM data from the drive (lvdisplay, lvremove, vgdisplay, vgremove, pvdisplay, pvremove, etc). Zeroing out the drive with dd would probably also work. Then you can mkfs. There you stupid, I told you to do so as I said! :)

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Pimp my VPS, linode.com

August 6, 2009 at 5:19 pm (English, Linux) (, , , , )

etienne@sigil:~$ uptime
11:27:25 up 276 days, 23:46, 1 user, load average: 0.00, 0.00, 0.00

Ok, ok, I know: uptime pissing match are lame and juvenile. Plus 276 days isn’t anything to write home about. I just couldn’t think of a better way to introduce this post, sorry.

sigil is my VPS hosted on Linode. Its main job is to host email for my personal domain, outlands.ca. It’s not a very hard job, it moves only a few hundreds email per day (the vast majority being spam, sadly). It also host my personal web space, which gets only a few hits once in a blue moon. All in all, the load average rarely ever get above 0.10.

However, email being my lifeline, it’s a very critical job. I used to host my mail on a real physical server co-located by a friend of mine. But last October, I had to move it fast as the machine had to be decommissioned pronto. Too bad, it worked like a charm for 3.5 years. Thanks a lot for that, Régis!

At first, when looking at my options, I was not too hot about VPS. The usual concerns about performance and security, you know them. But after some shopping around, it became clear that I could only afford a VPS, or tethering a server to my cable modem at home. I went with the former, being somewhat doubtful of my ISP reliability and not wanting to host a humming server in my basement.

Back then, the choice boiled down to either Slicehost or Linode. Slicehost was the better known option, but they just got acquired by Rackspace, a much larger (albeit respectable) company. I had read very good feedback about Linode on the intarweb, and decided to give a chance to the smaller guys.

Set up was very straightforward. I chose the smallest plan available at 20$/month and created an account. I chose their Ubuntu 8.04 LTS disk image, as I do not want to upgrade in the foreseeable future (it’s painful enough once every three years!). I was up and running in no time. Their VPS management toolchain is decent, with a pretty complete web UI (including DNS configuration), an AJAX console, configurable email alerts and an out-of-band ssh-based management console called Lish, which I do not use. All in all, pretty much everything I may ever need.

Now that I have used their service for nine months, I can really say I recommend these guys. My opinion is not fully enlightened, as I never used another VPS provider in the past and cannot make a useful comparison as such. But as Linode have been rock solid since I signed (hence the uptime), and never been down even once (that I noticed!), I am a happy camper. The network was a tiny tad laggy at time in the first couple months, but it have been very snappy ever since. Well, the IMAP server have been as snappy as IMAP can be, and the ssh keystrokes are appearing right away. What more can you ask for? :)

Now, on to the real purpose of this blog: pimping my referral code:

89d4968d3bda071f68c05be87c57581fcd9f0574

If this post was convincing enough that you decide to use Linode’s excellent VPS service, I kindly suggest you use the above ref code; I will get a 20$ credit if you keep the service three months. That’s what I call win-win-win (as there is three parties). So please do use it, and the karma shall be returned. Somehow. I promise.

If you wonder why I go to the trouble of hosting my own mail server when Gmail would be pleased to do it for free, that’s because I am a real email geek. And a tad too paranoid for my own good. But that’s for another blog post. :)

27/10/2009 Update: Linode just had their worst downtime ever. My VPS was down 6 hours today, and just got back up very recently :( Overall, I am still satisfied with the service, but this just goes on to say that it is not all peaches and cream either …

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Adieu, Agora

July 9, 2009 at 4:43 pm (Francais, Linux, Université Laval)

J’ai appris ce matin qu’Agora, le service de courriel étudiant de l’Université Laval, sera mis au rencart d’ici le début le la session d’automne 2009. Le service de courriel sera migré vers Microsoft Exchange 2007.

Ça me rend un peu triste. Je connaissais bien Agora. En fait, c’est mon bébé.

Agora a été mon premier gros projet d’infrastructure en TI. Ça m’a occupé à temps plein toute l’année 2002, et une bonne partie de 2003. À l’époque, j’étais employé par Linux Québec Technologies, un des premiers intégrateurs Linux du Québec. Mon patron avait gagné le contrat, non sans effort, de remplacer le système de courriel en place, qui souffrait de quelques problèmes de performance et d’extensibilité (il était sur qmail et qpopper, si je me souviens bien). Après quelques semaines de recherche et de prototypage, nous avons décidé de leurs offrir Cyrus imapd (en grappe Murder), Postfix et l’interface web Horde/IMP, le tout devant un équilibreur de charge redondant basé sur LVS. De la grosse quincaillerie, neuf serveurs en tout.

J’ai passé un bon de bout de temps à ré-écrire leurs outils de gestion maison, à interfacer avec leurs systèmes de batch job sur Oracle et à faire tout un paquet de modifications à Horde/IMP. Mon collègue Carol s’était occupé des équilibreurs de charge LVS. Le système a été mis en production en janvier 2003. Il y a eu quelques petits accrocs au départ, notamment une panne importante la fin de semaine du 9 mars 2003, où j’ai été rivé au téléphone pendant plus de 10 heures la journée du premier anniversaire de mon fils. :( Mais dans l’ensemble, ça s’est quand même bien passé considérant l’ampleur du projet et la complexité de l’infrastructure sous-jacente. La dernière fois où j’ai mis la main sur le système, il y avait 105K boîtes de courriel. Pas mal, quand même!

Après un peu plus de six ans et demi de bons services, Agora tire sa révérence. Je suis positivement surpris que le système soit resté en production si longtemps. Je crois que c’est un bon exemple de la fiabilité et de la pérennité des logiciels libres (le système est entièrement libre, sauf pour le filtre antispam). Si ça serait à refaire, je ne choisirais probablement pas Cyrus imapd en grappe Murder. J’irais plutôt avec des frontend Perdition et des serveurs Dovecot redondants en backend, et un référentiel de boîtes de courriel dans une base de données SQL plutôt que l’horrible système MUPDATE de Cyrus. Mais considérant ce que je savais et ce qu’on avait de disponible à l’époque, il semble qu’on a quand même fait de bons choix technologiques.

De façon assez étrange, le Service de l’informatique et des télécommunications (SIT) de l’Université justifie la migration du service vers Microsoft Exchange 2007 par le besoin de moderniser les infrastructures dans le cadre du projet Environnement numérique d’apprentissage (ENA) et de Modernisation des systèmes d’information de gestion des ressources humaines (MSIGRH). J’espère très sincèrement que ça ne signifie pas que nous, les étudiants, allons avoir à utiliser des technologies propriétaires de Microsoft dans le cadre de l’ENA. J’utilise Linux mur-à-mur, à la maison comme au travail, et je n’ai pas accès à un poste de travail sur Microsoft Windows. Il faudrait pas que ça m’empêche d’étudier à Laval!

Finalement, pour ceux que ça intéresse, j’ai laissé un Easter Egg sur Agora. Un indice: je suis un gros fan de The Matrix …

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