Mobile Vikings

Today is my 42nd day as a Mobile Viking. Call, sms and internet work perfectly and it is at least 50 percent cheaper than Belgacom Proximus! (No this is not an ad, I'm just happy for making a good decision.)


Vrije software

Dinsdagavond gaf ik op cvo tsm een inleiding van een uurtje over vrije software. Het event is gefilmd en zal binnenkort online komen. De slides kan u hier(pdf) al bekijken.

Achteraf lag ik er wakker van omdat:
- mijn verhaal er absoluut niet uit kwam zoals ik wou
- ik vergeten te melden ben bij de vier vrijheden dat je eigen interne aanpassingen *niet* moet vrijgeven onder de gpl.
- hoewel mensen op de achterste rijen mij perfect konden verstaan, had ik voor een aantal personen toch beter de micro gebruikt (er was 81 man)

De balans is gelukkig nog positief omdat:
- meer dan 40 van de 49 evaluaties toch wel extreem goed waren (allemaal 8/9 of 9/9 voor de vragen over de spreker)
- er maar twee evaluaties waren die mij niet willen terugzien als spreker
- ach ik heb weer iets bijgeleerd over spreken voor groepen
- er is een basis gelegd voor een goeie talk over vrije software


iSCSI mini howto

Some things in life, like iSCSI, are simple!
iSCSI is a protocol that allows you to have SCSI over IP.

The iSCSI Target

The host containing the physical hardware is called the iSCSI target and is easy to setup on Linux using iscsitarget.
aptitude install iscsitarget
aptitude install iscsitarget-dkms (Debian 6)

After enabling it in /etc/default/iscsitarget you can use files, hd devices, partitions, lvm volumes or software raid mdadm devices as 'physical hardware disks'
root@debby6:/etc/iet# cat ietd.conf
Target iqn.2010-02.be.linux-training:storage.lun1
IncomingUser isuser hunter2
Lun 0 Path=/iscsi/lun1.img,Type=fileio
Alias LUN1

Where /iscsi/lun1.img is a zeroed file created with
dd if=/dev/zero of=/iscsi/lun1.img count= bs=

Add the device to the allowed list:
root@debby6:/etc/iet# cat initiators.allow

and start the server. You should see this:
root@debby6:/etc/iet# cat /proc/net/iet/session
tid:1 name:iqn.2010-02.be.linux-training:storage.lun1
The iSCSI Initiator

The host that connects to this target server is called the Initiator. Most Linux distros have this available as open-iscsi.
aptitude install open-iscsi

A discovery will show available devices on the target:
root@ubu1104:/etc/iscsi# iscsiadm -m discovery -t st -p debby6,1 iqn.2010-02.be.linux-training:storage.lun2

Configuration with chap user and password takes a couple of commands:
root@ubu1104:/etc/iscsi# iscsiadm -m node --targetname "iqn.2010-02.be.linux-training:storage.lun1" --portal "debby6:3260" --op=update --name node.session.auth.authmethod --value=CHAP
root@ubu1104:/etc/iscsi# iscsiadm -m node --targetname "iqn.2010-02.be.linux-training:storage.lun1" --portal "debby6:3260" --op=update --name node.session.auth.username --value=isuser
root@ubu1104:/etc/iscsi# iscsiadm -m node --targetname "iqn.2010-02.be.linux-training:storage.lun1" --portal "debby6:3260" --op=update --name node.session.auth.password --value=hunter2

That's it! Now (re)start the open-iscsi service and use fdisk to see your iSCSI device.


November 2011 : No radio, no music!

In the news today: Taxi drivers will now have to pay a daily fee to play radio (or even music on CD for which they already paid). The fee goes to SABAM (think MPAA).

Radio used to be free, to promote music so people would go and buy music. But more and more everyone has to pay because people (could be) listening: first only concerts and parties, then work environments like shops, then waiting rooms, truck drivers, and now taxi drivers. How long will it take until there is a tax on our ears ?! No, I'm not kidding(*), the MAFIA(sorry I meant SABAM) will get there!

Who do we pay ?! The 200 people working for SABAM ? Talk to any *real* artist and ask them how much they get from SABAM, because it is supposed to be all for the 'poor' artists. We already pay the rich and powerful for the music we buy, we pay a second time for the storage media where we keep the music (cd/usb/harddisk,...), so starting today we will pay three times when taking a taxi while listening to our own music. We could soon be paying a fourth time via our monthly internet connection payments. And I am probably forgetting a couple...

Why do people accept this ? What's the benefit of hauling money to SABAM for society ? What do we get in return ? It seems to me that this is a classical story of the rich getting richer... for doing absolutely nothing.

We should all refuse to buy any kind of music, turn off the radio and not play any audio for a whole month! Yes, make November 2011 the month of protest against the storm on SABAM taxes.

(*) It reminds of an old story. Put a frog in boiling water, and it will jump out immediately. Put a frog in cold water and slowly heat it up... the frog will stay put and die. Slow increments are easier to accept than sudden changes, but the end result is the same.


Bluetooth and NXT setup

A reminder for myself on how to configure bluetooth for NXT devices.

Turn on all devices and activate bluetooth on the Linux, then:
$ hcitool scan
Scanning ...
00:16:53:08:XX:XX Julie
00:16:53:0B:XX:XX Mercedes

Then configure /etc/bluetooth/rfcomm.conf like this:
$ cat /etc/bluetooth/rfcomm.conf
rfcomm0 {
bind yes;
device 00:16:53:0B:XX:XX;
channel 1;
comment "Mercedes";

rfcomm1 {
bind yes;
device 00:16:53:08:XX:XX;
channel 1;
comment "Julie";

Then check the binding (as root):
# rfcomm release all && rfcomm bind all && rfcomm
rfcomm0: 00:16:53:0B:XX:XX channel 1 clean
rfcomm1: 00:16:53:08:XX:XX channel 2 clean

Then create an nxt.dat file in ~ :
$ cat /home/paul/nxt.dat

Then compile and download to the NXT:
nbc foo.nbc -O=bar.rxe
nbc -b -d -S=BTH::Julie bar.rxe


post-ubuntu install

Packages installed after default ubuntu install (personal bookmark).
root@mac:~# history | grep 'aptitude install'
11 aptitude install nvidia-settings nvidia-bl-dkms \
pommed vim nfs-common wicd
45 aptitude install azureus wesnoth chromium-browser
104 aptitude install virtualbox-4.0
139 aptitude install wireshark wireshark-gnome
152 aptitude install gimp
173 aptitude install openssh-server
180 aptitude install pdfedit
201 aptitude install ttf-bitstream-vera
206 aptitude install unrar
219 aptitude install imagemagick
220 history | grep 'aptitude install'


World ipv6 day!

8th of June is tomorrow already!
My humble contribution is to teach networking students tonight about ipv6. It will be mostly theory since the school doesn't support ipv6 on the network. Luckily I have some screenshots and wireshark sniffs from this morning of a working ipv6 connection to the internet.

One of the ipv6 test websites.

A tcp handshake and http connection over ipv6 (using 6to4).

And a PTR record in ip6.net with 32 child domains (okay you don't need ipv6 for this, but it is related).


another Microsoft virus...

Selecting an image on Google Image Search regularly minimizes the browser and pops up this annoying dialog.

Running Linux you know this is fake, but it is still annoying because (besides the minimizing of your browser) also opens a tab that refuses the back-button, and you don't get to see the actual image.

The first time this is funny (there is no C: drive nor a "My Documents" directory on "My computer").

Searching Google Images for something simple as "Axis Allies board 1984" and clicking on an image is enough to provoke it.

If you want to see the fun on Linux, use this link. Use at your own risk ;-)


(the url might not work since I reported it )

Click OK on this last dialog to close the tab.


loadays talk

Some people convinced me to do a talk^Wtutorial tomorrow at loadays. It will be about bash!

Maybe I will use some slides from this downloadable pdf (50KB).

Content will come from the linux-training.be project (but that website stalled since February due to a redesign of our build-system). People that go to loadays can download the newest (1MB) pdf here.

LOAD, the Linux system administrator days


clear zfs properties

Default zfs properties can be read with zfs get.
root@sol11aa ~# zfs get -r quota rpool/mita
rpool/mita quota none default
rpool/mita/jenna quota none default
rpool/mita/josep quota none default

These properties can be changed with zfs set.
root@sol11aa ~# zfs set quota=2gb rpool/mita/jenna
root@sol11aa ~# zfs get -r quota rpool/mita
rpool/mita quota none default
rpool/mita/jenna quota 2G local
rpool/mita/josep quota none default

And they can be cleared by setting the property to none, but the source is now set to local instead of default.
root@sol11aa ~# zfs set quota=none rpool/mita/jenna
root@sol11aa ~# zfs get -r quota rpool/mita
rpool/mita quota none default
rpool/mita/jenna quota none local
rpool/mita/josep quota none default

This local can be restored to default using zfs inherit.
root@sol11aa ~# zfs inherit -Sr quota rpool/mita/jenna
root@sol11aa ~# zfs get -r quota rpool/mita
rpool/mita quota none default
rpool/mita/jenna quota none default
rpool/mita/josep quota none default


nine provinces in Flanders ?

Radio 1 this morning discussed a proposal to split Flanders into nine provinces. Disregarding the fact that I oppose the eight layered governance of a random street(*) in my city, I would like to redraw the current map of Flanders.

One of the main issues that prevents this country from having a government resolves around (imho ridiculous) language problems in and around Brussels (the brown area). Brussels is surrounded by (officially) Dutch speaking communities, but is itself mainly French-speaking.
Bad governance between 1970 and 2010 resulted in discrepancies (for instance: French-speaking people in Dutch-speaking territory BHV can vote for French-speaking politicians, but Dutch-speaking inhabitants of the French-speaking part of Belgium cannot vote for Dutch-speaking politicians).

Also, Brussels is structurally way too small to make decisions that it should be capable of making (about its airport/highways/public transport/industry/...), since those are mainly in Dutch speaking parts outside Brussels (falling under another government).

The new map:

This new map enlarges Brussels so that it can manage the areas that currently surround Brussels but that economically and structurally belong to Brussels. Another advantage is that adding more Dutch-speaking people to Brussels makes it more balanced linguistically.
The red part is the new province of Leuven. Some municipalities from the former province of Vlaams Brabant migrated to neighboring provinces.

(*) Depending on what happens in a random Antwerp street, one or more of the following eight 'governments' is responsible:
- district (part of the city)
- gemeente (the city council)
- kanton (district, smaller than a province)
- provincie (province)
- gemeenschap (the Flemish Community)
- gewest (the Flemish Region)
- land (Belgium)
- Europese Unie (European Union)
What happened to the KISS strategy ?!


orca magnifier ?!

Yesterday I tried setting up orca magnifier on a freshly installed (fully updated) Ubuntu 10.10. The moment you check the magnifier checkbox the screen becomes garbled (all window borders disappear, about one quarter of the screen is magnified, the rest is garbled). The 'apply' and 'cancel' buttons are invisible (yet they work if you can guess their position).

Switching from the default to nvidia drivers makes no difference.

First we tried on an Acer Aspire 17-inch laptop, next we tried a 15-inch Apple Macbook Pro. The results are identical!! (yes i tried removing the orca config, creating a new user, reboot, ...)

Is there an alternative for orca magnifier ? (Because the Ubuntu/Orca forums don't help much.)

Will it work in Debian or Fedora ? (I would have to burn the cd and drive 100km to test this...)

Do you know people that actually use orca magnifier on Ubuntu ?