Feb 20, 2017

EdCamp Bali 2017: going international

This April 22nd, we are going at it again. If you have never been to an EdCamp before, why not try ours?

It's going to be a fun-filled day of learning from each other. Hope to see a lot of people there!

Go here to register!

If you have never been to an EdCamp, I like this video to get an idea of what it is:

Jun 6, 2016

Leaving your school, but want to take your Google Classroom work with you?

Teachers around this time of the year are finding out that Google Takeout does not include Google Classroom (yet?). Using Takeout will work great for all the Google Drive content that you own, and this will include content that you have created for your Google Classroom. (NOTE: Watch out for files in your Google Drive that you care about, but actually are owned by someone else! Make copies of these files before you use Google Takeout.)

What about all the announcements, quick reminders, etc... that you have in your Google Classroom streams, or in the About pages? I couldn't find anything officially supported, sot his is what I recommend as a temporary solution:
  1. Use Google Takeout to get all the Google Drive content from your account, which should cover all the documents you posted on Classroom, for most people.
  2. Open the Classroom stream, and scroll down to the bottom. It loads dynamically, so you need to keep scrolling down until you see the entire course from the very first post.
  3. Note: if you care about keeping the student comments, you will have to expand them for each post as you scroll down.
  4. Use the Print function of your web browser, and print to PDF. In Google Chrome, this works best (for me), with Margins set to minimum, Portrait layout, and the Background Graphics checkbox turned on.
  5. Save that PDF somewhere safe!
  6. Repeat for all your other Classrooms.
It's not ideal, but you at least get to keep a pretty decent copy. Even the links should be there!

Jan 21, 2016

Using SiS 771/671 graphics card with Ubuntu 14.04

Just a quick post to avoid losing this very useful bit of information: we have some older laptops laying around that were budget bargains. They have the following (old!) SiS graphics card:

01:00.0 VGA compatible controller [0300]: Silicon Integrated Systems [SiS] 771/671 PCIE VGA Display Adapter [1039:6351] (rev 10)

After trying in the past several times, somehow today my Google-fu was strong, and I found two useful bits of information:

  1. This PPA for Ubuntu 14.04 and 15.04 that holds the driver xserver-xorg-video-sisimedia, created by mati75:
  2. ArchLinux has the same driver available, so if/when this driver for Ubuntu is no longer viable, I get an excuse to play around with Arch! Awesome!
Following the instructions on the PPA page, I was able to get the laptops to use the native 1280x800 resolution, instead of 640x480. Ubuntu went from absolutely unusable to a very nice option! (using Lubuntu, by the way, but Xubuntu would probably also work decently.)

Dear mati75, Mateusz, thank you for creating that PPA!

Update: To help people in finding this, the laptop model information, from the BIOS. Notice the great serial number. Shame on you, Clevo.

root@user-M7x0S:~# dmidecode -t 1
# dmidecode 2.12
SMBIOS 2.4 present.

Handle 0x0001, DMI type 1, 27 bytes
System Information
        Manufacturer: clevo                           
        Product Name: M7x0S                           
        Version: Rev. A1                         
        Serial Number: 12345678901234567               
        Wake-up Type: Power Switch
        SKU Number: Not Specified
        Family: Not Specified

Oct 30, 2015

Better rendering of Windows C-fonts (Calibri and others) on Linux Mint and Ubuntu

Recently I've been working on Linux Mint for my school and some of my friends. They needed to get Calibri and all the other Office fonts rendering decently on Linux to help in exchanging files with other people.

The problem is that these fonts have embedded bitmap versions of very low quality, and the font rendering system on Linux will choose these in too many cases. Modern fonts do not have bitmap versions, which is why every other font that is not from Microsoft will work beautifully on Linux.

The fix is to tell Linux to not use the embedded bitmaps in font files.
I want this setting to be applied to all users, so here are the instructions.

1- Open a terminal, and type:
sudo gedit /etc/fonts/conf.d/20-no-embedded.conf
You will need to enter your password.

2- Paste these lines in the text editor:

<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
  <match target="font">
    <edit name="embeddedbitmap" mode="assign">

3- Close and save that file. To be absolutely sure the setting is applied, reboot your computer, or at least log out and log in.

That should do it!

Found at (among many other places):

Alternatively, you can use the fonts "Carlito" and "Caladea" instead of "Calibri" and "Cambria". Install them with this line:
sudo apt-get install fonts-crosextra-.*
Then you can use LibreOffice's font substitution table in the Options, to use Carlito and Caladea whenever it finds Calibri and Cambria in a document.


The Debian wiki also has a great explanation:

However, be warned that the proprietary versions will likely look much worse on your screen than the OFL ones. This is because Microsoft decided to embed surprisingly bad bitmaps in their fonts and Debian's fontconfig does not disable embedded bitmaps in scalable fonts.

Aug 12, 2015

Getting Google Classroom in English (or some other language)

Alright, so it seems Google Classroom is still not wise enough to use the language that you have configured in your Google Account or in your web browser language preferences (see here, for example).

While the Google engineers work their magic, you can use this nice link here to get to Google Classroom in English:


Here are two more:

If you want to do it by hand:
  1. Open Google Classroom in your favourite way.
  2. Click on the web browser's URL bar.
  3. Go all the way to the end, and add (without the quotes) "?hl=en"
  4. Press Enter

PS: Maybe this was this year's only and lonely blog post. Who knows? :)

Oct 21, 2014

BackupPC and Windows servers - Simple method

Slightly insecure, due to storing the user password, encrypted, on the client machines. See here:
http://cygwin.com/cygwin-ug-net/ntsec.html - section "Switching the User Context, Method 3"
The idea is to be able to backup all files, including open files ("locked"), by using VSS (Volume Shadow Copy Service).
You will need the files that I've shared here.
  • Add the domain user called "backuppc", using the Computer Management program in Control Panel, Administrative Tools. Make this user administrator of the local machine.
  • Download Cygwin 1.7+ from the regular place: http://www.cygwin.com/
  • Install the default Cygwin system, plus the following: cygrunsrv, openssh, and rsync
  • I also install nano (my editor of choice), and procps (for top)
  • Start a cygwin shell and type:
# ssh-host-config -y
# cygrunsrv -S sshd
# mkpasswd -l -u backuppc -d YOURDOMAIN.COM >> /etc/passwd
  • After doing this, check /etc/groups, make sure that the Domain Users group is added. If not, add this line to the end of the file:
    Domain Users:S-1-5-21-3835976426-429400520-196227251-513:10513:
  • I then attempt to ssh into my backupPC system from cygwin, just a nice test, and creates the .ssh directory for me.
  • Copy BackupPC’s public key over, by running this from the SRVR-UBackup server:
# ssh-copy-id backuppc@windows-server-name
  • Connect through SSH to the new server, and run this to store an encrypted copy of the user password on the new server:
    # passwd -R
  • Doing this allows the user to execute administrative operations when logging in using SSH passwordless authentication. Somewhat insecure, but easiest to set up, and should be reasonable in our case.
    NOTE: If it fails, try logging into the server with Remote Desktop as BackupPC, then run the Cygwin terminal as Administrator (righ-click).
  • Install the post-backuppc.sh and pre-backuppc.sh scripts from Windows-vShadow-simplified.zip to the backuppc home directory. Remember to make them executable (chmod +x), and make them owned by BackupPC@yourdomain.com
    NOTE: Carefully edit it to match the drives of the new server that you plant to back up.
  • Install the appropriate vshadow.exe from vshadow-versions.7z in C:\WINDOWS of the new server. Several versions are attached below. Make sure you rename it to vshadow.exe
  • Test the process by doing ssh to the new server as user backuppc, and running /home/backuppc/pre-backuppc.sh. You should see shadow drives come up in C:\shadow.
  • In the BackupPC configuration for the host, change the following:
    • Xfer:
      • RsyncClientCmd:
        $sshPath -c blowfish -q -x -l backuppc $host $rsyncPath $argList+
      • RsyncClientRestoreCmd:
        $sshPath -c blowfish -q -x -l backuppc $host $rsyncPath $argList+
    • Backup Settings:
      • DumpPreUserCmd:
        $sshPath -c blowfish -q -x -l backuppc $host /usr/bin/bash -l -c /home/backuppc/pre-backup.sh
      • DumpPostUserCmd:
        $sshPath -c blowfish -q -x -l backuppc $host /usr/bin/bash -l -c /home/backuppc/post-backup.sh

Nov 13, 2013

The next bubble to burst: how long will we have all these free cloud services?

A couple of weeks ago, I found this interesting blog post:
Microsoft Price Increases: Here it Comes Again!

The topic is quite obvious, but here is the quote that actually stuck out for me:
Anything being sold “as a service” to an enterprise today is probably being sold at a big loss in order to gain market share. Whether it’s Microsoft, Amazon, or someone else, the pricing is not sustainable. Subsequently, expect future cost increases to be much larger than the ordinary rate of inflation.
What does this mean, in practical terms? I believe we are in a "free cloud services" bubble, and that this quote means it is about to burst.

Amazon runs two very important cloud IaaS - Infrastructure as a Service - products: EC2 and S3. When they introduced EC2, they disrupted dramatically the hosting market. Suddenly, you could run your own server on Amazon's CPU power, on a "pay-as-you-go" model, at rock bottom prices. And you could store all of your server's data on S3 for equally disruptive rock bottom prices.

This enabled the appearance of a large amount of free cloud-based products that many educators know and love: Dropbox, Pinterest, Instagram, Voicethread, Edmodo... You can find some more interesting examples in their case studies page.

Amazon has been effectively subsidizing the EC2 (and all their other Amazon Web Services, quite a lot of them) with other parts of their business, to become the main player in this space. Eventually, they will need to increase their pricing to bring it back to sustainable levels. A price increase on Amazon's side will also enable Rackspace, Microsoft's Azure, and other cloud IaaS providers to increase their pricing in parallel. See above: "increases much larger than the ordinary rate of inflation".

When that happens, we will see a lot of their customers, all these free cloud providers, struggle with their business models. The key question is: How many of them will successfully absorb the increased costs? How many will choose to pass on these costs to their users?

What I see is a bubble about to burst. And we will need to get used to either paying for our cloud, or give it up.

What do you think? How much are you ready to pay for your cloud?