//extrabright

Check out my new mix in the sound section! I did something a bit different than the previous time, as I wanted to explore the electro-rock style, which is really a great and energetic combination.

• Extrabright Mix 02: From electro-rock to minimal, with an electronica introduction and a new age epilogue. Calvin Harris remixed by Mr. Oizo, Ellen Alien, Justice, Miss Kittin, Love Motel and a couple of other great tracks.
  

Just installed a Wordpress plug-in that aims at providing a good rendering on the iPhone. It’s called WPtouch. Neat.

I had some database issues 2 weeks ago, therefore I lost a couple of comments. Sorry guys. I hope it will stay stable now.

Cheers!

Just figured out how to get Twitter update the pidgin status (e.g. GTalk, Jabber, ICQ, MSN, etc.). For that, you need to install a pidgin plug-in written in Perl. Here is a small howto about it (as the Perl stuff was a bit tricky):

Install Perl. On Windows (yeah, I know. It’s at work. ), install Active Perl version 5.8.8.X. Don’t take the last one, the 5.10.0, as Pidgin does not support it yet.

Testing the wordpress application on the iPhone. It seems quite easy to post something. Apparently it works also on a self-hosted wordpress instance.

Just trying the Flock browser for posting a blog news. It’s great. It’s about like writing an e-mail, with a good blog integration, where you can define tags, categories and that kind of news-related things. Really cool. Much quicker than the web interface.

I published some time ago a news regarding reducing the power consumption of my home server to 53 W. There was some open issues like how to reduce the consumption further.

Regarding this, I finally simply decided to switch off the server automatically every night using a Cron job. This is an elegant solution, as I am not hosting anything on this home server, other than stuffs I am using at home. Everything else is on my dedicated server.

This solution has the following two advantages:

What I can still improve:

Will check this out.

Something I wanted to do since ages. My wireless router WRT54GL running the Tomato firmware has a button on the front, which can be used to toggle WIFI on and off. The router has also a rather visible LED indicator, behind the button, that is unfortunately not used to show the WIFI status. (Originally, the wifi status is just shown by a tiny LED, that is just visible when watching closely the device).

It’s easy to fix that. Using the web interface, go to the ‘Administration’ > ‘Buttons / LED’ page. Replace the custom script by the following code:


# status: 1: wifi on, 0: wifi off
status=$(wl -a eth1 dump | grep associated | cut -d " " -f 2);
# toggle wifi & amber led
wl -a eth1 $([ $status -eq 0 ] && echo up || echo down)
led amber $([ $status -eq 0 ] && echo on || echo off)


Then change the setting for ‘0 - 2 Seconds’ to ‘Run Custom Script’. That’s it. Now when we press the button, the wireless is toggled and the LED switches itself accordingly.

Tested with Tomato 1.19.

According to the free newspaper “news” of today (Zurich, Switzerland) page 15, the computer-science Professor Kieron O’Hara, which is concerned about the loss of privacy in the internet age, is advising the editor in the interview to “google regularly one’s name, phone number and credit card number”, to see if this information is to be found somewhere on the net. OMG. I am wondering where this crap comes from. Either is this professor as intelligent as my banana tree, or the editor writing this did the interview in Esperanto, which neither of the two are understanding.

Why is it a bad idea to google one’s credit card number? Just in case you don’t know.

I have watched this talk a couple of days ago. It is really interesting so I am posting it hereafter.

I like particularly the TED talks. They are creative, expose innovative ideas in the fields of science, art, education, technology, design and even spirituality. It is a great source of inspiration. Now with leopard I can also watch my TED podcasts on TV using the new frontrow application. This is awesome.

In The following talk, Ken Robinson talks about creativity and education in “Do schools today kill creativity?”.

I just stumbled upon that video of Justice on Youtube. There is definitely something interesting there!

I just put a new mix in the sound section, so check it out! The mix is encoded at 256 kbit/s, I hope that’s OK for streaming. It should be, at least with the present band width we have.

• Extrabright Mix 01: House to techno with a pinch of trip-hop, from John Aquaviva to Mike Ink, from Da Minimal Funk to a revisited version of Dimitri of Paris’ famous Back in the Daze, to name just a few.
  

Last week I bought a consumption measurement device for 20 bucks. I wanted to know how much current is needed for various electronic devices I use at home, some of them on a 24/7 basis. I have got a home server running Linux, that I use as a NAS, print server, slim server (for streaming mp3 files to an mp3 device) and for experimenting a bit with Xen and Ubuntu. I have got also some other devices like a wireless access point (WRT54GL running Tomato), a cable modem, an external backup hard disk, a b&W laser printer and a few other electronic devices.

Of course, one of the most energy hungry device I have is the server, which is always switched on. I was expecting a consumption of about 60 W, because I tried to choose efficient components, some of which were listed on a review regarding a green computer consuming 54 W when idle. My hardware configuration is the following:

• Processor AMD 64 x2 EE 3800+, dual core and energy efficient version (which is actually quite cheap)
• Micro-ATX Mainboard M2NPV-VM with AM2 socket
• 2 GB of RAM (DDR2 PC4300)
• 2 Seagate 7200.8 250 GB hard disks used as a software RAID-1 array
• Power supply ElanVital 500W, ATX, with 80% efficiency.
• Plextor Plexwriter DVD burner

So I shut downed my server, plugged it in the measurement device and booted it. The value I could read on the device, after the reboot was finished and the server was idle, was higher than expected: 85 W. I was not very happy with that value and began to try to optimize it.

• I first tried to remove the DVD burner, but I got just 2 W of reduction, which was not good enough.
• Then yesterday I tried to install the last stable release of Ubuntu, which is Ubuntu 7.10 gutsy 32 bits version (I add previously Ubuntu feisty with a XEN enabled kernel). I was pleased to see that the server was only consuming about 68 W (DVD burner included). I then tried to re-install XEN and after rebooting saw that I was again at 85 W. So the XEN kernel had different options enabled that were not optimized for a good power management.
• I got back to the stock kernel and tried to activate the automatic spin-down of the hard disks. I did this using the command

  hdparm -S 60 /dev/sda
  hdparm -S 60 /dev/sdb

  which spins down the two disks after being idle for 5 minutes. I was able to grab a few watts and get down to 60 W, which is not too bad. I added the two commands in /etc/rc.local so that it gets executed automatically on boot.

• I then tried to activate the automatic CPU frequency scaling, so that when the processor has a low usage, its frequency gets automatically reduced, hence saving some energy as well. I was getting some problems using the module powernow-k8, so I updated the bios to the latest version (1201), which resolved that issue. I could then install correctly the cpu scaling daemon. I just had to run

  apt-get install cpufreqd

  and then edit the file /etc/default/cpufreqd and insert “powernow-k8″ in the option CPUFREQ_CPU_MODULE (you can check which module you need to use here). With these two operations, the BIOS upgrade and the cpu frequency scaling, I was able to grab a few watts, getting down, when the server is idle, to about 53 W, which is already a lot better than the 85 W I was getting without tuning.

The options I might consider now are the following:

• I could reduce significantly the power consumption if I automatically switch off the server every night. I am using it also to do a distant backup of another computer, but I could setup the BIOS to switch it on every night to do that, if it is not already the case. The only thing I would need to do is just to switch the server on, whenever I want to print something or hear mp3’s, which is not too bad. The server would then switch itself off at night, after doing the backup.
• If I want to use XEN, I should compile my own patched kernel (for XEN) and tune the power management options to get the same consumption as on the stock kernel.
• I could try to tune further the kernel options, which I am not sure that I am going to do, as it is much more convenient to use the stock kernel than to use a self compiled one (e.g. for updates).
• I could try to find a way to cut off the consumption of some other electrical devices, which are most of the time not used or in standby mode, but do consume power anyway. Like for instance the laser printer (standby 14 W), the external backup hard disk Seagate 500 GB 7200.10 (standby 12 W), the wireless access point WRT54GL (always on, 14 W) or the cable modem (always on, 12 W). Not sure how I can do that. Of course I could plug some of these devices in a multi socket with a switch, but I would need to turn it on each time I want to access the internet using my laptop and turn it off afterwards (in addition it’s not compatible with my automatic distant backup). Not very elegant. I guess I will have to think about that issue.

Additional links:

• How to reduce power consumption Nice howto based on Linux with other options presented.
• Ubuntu forum post Use cpufreqd to tune CPU frequency
• Ubuntu forum post Which module to use for cpufreqd

“Un style, plus qu’un parti, a triomphé le 21 octobre: l’autoritarisme émotionnel, dont un bon exemple nous vient de la Russie.”

Article intéressant sur largeur.com au sujet des élections du week-end passé. Je vous en conseille la lecture.