Patrick Truchon's Web Portal

Archive for April, 2010


Posted by Patrick on April 24, 2010

(Photo by natetherobot licensed CC By-Nc-Na.)

The Hard Way

We all know that we should backup our files regularly, but most of us don’t.  Who wants to spend half an hour every few days sifting through folders and copying important files on an external hard drive.  Of course, one way to not think about this process is to simply copy everything, but that takes a lot of extra disk space and a time.  Thinking this way about backing up is the same as thinking about cleaning your desk: it takes precious brain resources, and time.

The Automatic Way

The thing is, though, that backing up is not at all like cleaning a desk.  We’re not good at doing repetitive work, but computers are; all they need are clear instructions: what to backup, and where to back it up.  There are lots of free backup utilities [1] to help give those instructions, but not all of them are that good.  Here are three basic features a good backup utility should have:

  1. The first time you use it, it should help you decide what you want to backup, then it should be able to do its job as often as you need it to without bugging you again.
  2. To save time, it should be able to know which files changed since the last backup and which didn’t, and only copy those that changed (instead of all of them).
  3. It should keep different “versions” of your backups so you can travel back in time when needed.  But to save disk space, it shouldn’t duplicate the actual data of different versions when it’s the same.

What I Do

I searched a long time for a utility that could do all of this, but found that most of them added too many unnecessary features or were too “user friendly” by forcing me to use an automatic recovery procedure that made the whole thing kind of cryptic.  If I ever need to recover a lost file, I don’t want to just press a button to recover the whole thing, I want to navigate to my file and recopy it to my computer.  Not wanting an “auto-recovery” feature may seem like a step back, but I have two reasons for this: first, most of the time, when I need to recover files, it’s because I made a mistake by deleting them, not because my system crashed.  But even in the event of a system failure, I would probably use the “opportunity” to install a new system, so I don’t necessarily want to recover all my files.

In any case, what I wanted was a backup utility, not a recovery program.  So finally, after failing to find what I wanted, I ended up writing my own backup script using rsync [3] and cp -al [4].  Here is what it does.

  1. First, I need to tell it what I want to backup and where.  I do this (only once) by editing the script.
  2. When I’m ready to backup, the first stage of the process copies the files.  The program rsync looks at the folder I want to backup and makes itself a list all the files in it (with some details like their size, date of last change, etc.).  Then, it does the same thing with the backup folder.  Finally, it compares the lists, deletes the items from the backup folder that are no longer on my computer, and updates the ones that have changed.
  3. Finally, the program cp -al (on GNU/Linux) or cpio (on OS X) makes what seems to be a copy of the entire backup folder and adds the date.  The important difference is that it doesn’t actually copy the files, but created hard links [5] instead.  What that means is that even though it looks like there are two folders containing the same data, they are actually two folder names sharing the data.  When I make a new backup, the recent folder will be updated (in step 2), and a new hard link copy will be made.  Each time, the hard linked copies share the data that hasn’t changed, but possess their own versions of the files that are different.

The Result

The only thing I have to do is press on a button to load the script, enter my password, and watch the whole thing go.  At the end, I get a new version of my backup sitting along side the previous ones. If I check the size of each of these folders, it looks like they are all about 170GB in size.  In truth, though, all these folders share most of the data.  When I use a different way to look at the size, I see that the first backup has the biggest size, and the newest backups are smaller since they only contain the “difference”:

ptruchon@Home:/media/HD$ sudo du -shc *

93G BackUp_20091113_030205
81G BackUp_20091206_095256
12G BackUp_20100105_103154
4.3G BackUp_20100120_064439
7.3G BackUp_20100203_064727
6.9G BackUp_20100209_202706
795M BackUp_20100301_063811
659M BackUp_20100312_152826
788M BackUp_20100322_232813
9.8G BackUp_20100329_093746
1.3G BackUp_20100401_105604
1.2G BackUp_20100415_093503
3.0G BackUp_20100418_063632
878M BackUp_20100421_224022

At School

At our school, we also give all our students 3GB of server space to store their files or post things online.  I’ve adapted my script so that every student can backup their school folder (not their entire computer) to their server space easily.  Here’s a quick introductory video demonstrating the procedure in Quicktime or ogg Theora format.

To use these scripts, you need to be using GNU/Linux, or Mac OS X (sorry Windows).  Simply download them from my Webfolder [2] and read my Wiki Notes [6] for more information.  I will probably add more detailed instructions later, but feel free to email me if you have any questions.


  1. Life Hacker: Backup Utilities, <>
  2. Patrick Truchon’ Webfolder: Bash Scripts, <>
  3. Wikipedia: Rsych, <>
  4. Wikipedia: Cp, <>
  5. Wikipedia: Hard link, <>
  6. Patrick Truchon’s Wiki Notes: Shell Scripting, <>

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Posted by Patrick on April 10, 2010

Quirks & Quarks [1] is a Canadian weekly science news program heard over CBC Radio One.  Since 1975, it has been hosted by David Suzuki (1975-79), Jay Ingram (1979-91) and Bob McDonald (1992-now).  [2]

I’ve been a big fan of Quirks since the end of the 90’s.  Back then, the Internet was slow so I would actually tune in to Radio One at precisely the right time of the week to spend an hour listening to Bob’s fascinating interviews.  Nowadays, his program is part of my RSS news reader, and I download the interviews that might interest me to my Android phone.  Times have changed, but the program is still as good as it used to be.

About eight years ago, I noticed something new on Quirks web site: a link called “what is ogg“.  Following it, I learned that the new audio format offered by Quirks was:

“Ogg Vorbis, a new audio compression format [that] is roughly comparable to other formats used to store and play digital music, such as MP3, VQF, AAC, and other digital audio formats. It is different from these other formats because it is completely free, open, and unpatented.” [3]

That simple link, offering me to download an ogg file instead of an mp3, lead me to learn more about open formats [4] and the whole issue of patents in computing.

Unfortunately, since September of 2009, Quirks has dropped the ogg format.  Because I filter their website through my RSS reader, I only noticed that last week.  But when I asked them about it (on April 7), [5] they promptly replied:

“We stopped due to lack of use and lack of demand. Only a handful of people were using them – which did not justify the extra work involved.

Hope you will continue to listen to the program. Thanks for writing.”

I replied to them again on that day to explain the educational value that offering such a format provides, but I’m still waiting for an answer.

Here’s a quick break down of the audio formats that Quirks has offered over the years:

If, like me, you think that our national radio should lead by example and use Open Formats, write them a little note.


  1. Quirks and Quarks, <>
  2. Wikipedia: Quirks and Quarks, <>
  3. FAQ, <>
  4. Wikipedia: Open Format, <>
  5. Quirks and Quarks: Contact, <>

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Digital Citizenship

Posted by Patrick on April 7, 2010

First, Inform yourself:

Then, Spread the word [1]

Finally: Act [2]

–Update– And when it fails:  Mobilize [3] and  Rebel [4]


  1. Stef, Debillitated, <>
  2. Glyn Moody, <>
  3. Twitter, #debill, <>
  4. Whatdebill, <>

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Posted by Patrick on April 6, 2010

“TiddlyWiki is a single html file which has all the characteristics of a wiki – including all of the content, the functionality (including editing, saving, tagging and searching) and the style sheet. Because it’s a single file, it’s very portable – you can email it, put it on a web server or share it via a USB stick.” [1]

That’s the technical intro to TiddlyWiki.  On the educational side, TiddlyWiki allows us to take notes in a non-linear way.  Although I’m still on the look out for potential uses of this tool in my (math) classes, I can definitely see how this could be useful in Humanities and Language Arts classes.
I’m running a little experiment to see how it could be used to take reading notes.  As I’m reading Alan Story’s book [2], I’ll be taking notes on this TiddlyWiki [3] trying to figure out how best to organize those notes as I go along.  I’ll report back later…  In the mean time, feel free to give me suggestions.


  1. TiddlyWiki, <>
  2. Alan Story, An Alternative Primer on National and International Copyright Law in the global South: Eighteen Questions and Answers,
  3. TiddlyWikiCitizenShipReadingNotes, <>

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iPads for a 1:1 School?

Posted by Patrick on April 3, 2010

A Recipe?

I’ve been giving a lot of thoughts lately about what the “best way” of implementing a 1:1 laptop program is.  Thinking about questions like:

  • What kind of computers and OS should students use?  Should they all use the same or one of their choosing?
  • What kind of applications should students use?  “User friendly” but non-free?  Free (and Open Source) but less convenient?
  • What constitutes appropriate (and inappropriate) use of technology?  When?  On campus only?  Anytime and anywhere when it’s online?
  • In a remix culture, what does plagiarism mean?  Can a line be drawn between collaborating, re-mixing, and plagiarizing?  How?

Not surprisingly, I’m coming to the conclusion that there is no ready-made recipe to navigate these “problems”.  They simply have to be acknowledged as real, important and consequential issues, and then addressed by the whole school community.  These are the type of questions that a special school committee (that includes students) should grapple with for the good of their own school, not the type of questions that have pre-digested answers for all.


Keeping that in mind, I’d like to suggest a definite “non-answer” to the first question: the iPad is not a good device to use for a 1:1 school.  One of the reasons (which I won’t expend here) is that the iPad is incompatible with ideals of digital freedom.  Even if it had promising educational uses, it’s one of those things that we should avoid as much as possible. [1]

Apart from that issue, I think the iPad is simply not a device conducive to unforeseen creative uses.  I am *not* saying that it can’t have any creative use what-so-ever.  If creative teachers can find relevant uses for mobile phones or portable media players, surely they can find something for the iPad.

Jeff Utecht focuses on the creative aspect of the iPad when he writes:

“Apple’s own iPad website states: “The best way to experience the web, email, photos, and videos.” That might be so, but what’s the best way to create web pages, emails, photos, and videos? […] That’s the device I want in the hands of my students!” [2] (emphasis is mine)

Although he’s right, I think he’s being too gentle by leaving out the unforeseen part.

Generative Technology

In his book, The Future of the Internet, and How to Stop it, Jonathan Zittrain develops the concept of “generative technology”.  Such technology invites people to tinker with it.  Its creators may have had an idea of how it would be used, but they left it open to the users to come up with their own applications.  Zittrain contrasts two devices from Apple, thirty years apart:

  • In 1977, the Apple ][ was a blank slate.  It quickly became popular two years later when VisiCalc (the first spreadsheet program) was written by an independent programmer.  Apple had no way of knowing that this would happen.  “They had their hunches, but, fortunately for them, nothing constrained the PC to the hunches of the founders. Apple did not even know that VisiCalc was on the market when it noticed sales of the Apple ][ skyrocketing.” [3, p.2]
  • Thirty years later, “[t]he iPhone is the opposite. It is sterile. Rather than a platform that invites innovation, the iPhone comes preprogrammed. You are not allowed to add programs to the all-in-one device. Its functionality is locked in, though Apple can change it through remote updates. Indeed, to those who managed to tinker with the code to enable the iPhone to support more or different applications, Apple threatened (and then delivered on the threat) to transform the iPhone into an iBrick. The machine was not to be generative beyond the innovations that Apple (and its exclusive carrier, AT&T) wanted.” [3, p.2]

In that respect, the iPad is not much more than a bigger iPhone.  But isn’t the difference outlined by Zittrain only relevant for programmers?

Beyond Expectations

As a teacher, it’s always my hope that my students will go beyond my expectations.  The type of tools they use implicitly tells them something about the height of those expectations.  By giving them a computer with a list of possible programs they can download, install, and use to complete a project, I’m telling them: “be creative and impress me”.  By giving them a tool that can only run certain applications, I’m telling them: “this is how I want you to do this”.

Cory Doctorow puts it well when he writes:

“Buying an iPad for your kids isn’t a means of jump-starting the realization that the world is yours to take apart and reassemble; it’s a way of telling your offspring that even changing the batteries is something you have to leave to the professionals. […] The real issue isn’t the capabilities of the piece of plastic you unwrap today, but the technical and social infrastructure that accompanies it.  If you want to live in the creative universe where anyone with a cool idea can make it and give it to you to run on your hardware, the iPad isn’t for you.” [4]

In my classroom, I want my students to be creative in ways that I might not have foreseen.  On the surface, the iPad may solve problems of “inappropriate use of computers” (or not), but it doesn’t deal with them.  And then, students loose on all the potential for creativity that a blanker slate offers.


  1. Patrick Truchon, Just Because it Works…, <>
  2. Jeff Utecht, The iPad: Not the Right Product for Education, <>
  3. Jonathan Zittrain, The Future of the Internet and How to Stop it, <>
  4. Cory Doctorow, Why I Won’t Buy an iPad, <>

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