Booting Ubuntu-14.04 cloud images without a cloud


So, Ubuntu-14.04, Trusty Tahr, is out; and booting the cloud images requires a bit more hacking than booting the 12.04 cloud images. Here goes:

Get the image, resize and loop-back mount it:

qemu-img convert -c -O qcow2 trusty-server-cloudimg-amd64-disk1.img trusty-server-cloudimg-amd64-disk1_30GB.qcow2
qemu-img resize trusty-server-cloudimg-amd64-disk1_30GB.qcow2 30G
sudo modprobe nbd
sudo qemu-nbd -c /dev/nbd0 `pwd`/trusty-server-cloudimg-amd64-disk1_30GB.qcow2
ls image || mkdir image
sudo … Read the rest

Booting Ubuntu-12.04 cloud images without a cloud


I was recently asking myself why the P2V concept has not been more fully embraced by the open-source community – and generalized to V2C, virtual machine to cloud instance. From a scientific computing perspective, it would be ideal to seamlessly be able to prototype a data analysis in a virtual machine on a laptop and then run large-scale data … Read the rest

Backup Google Drive / Docs

Cloud storage is often used for backup, but finding myself relying more and more on cloud-only documents, I felt a need for backup in the opposite direction: backing up my entire Google Drive to local storage – preserving the folder hierarchy. I was not able to find a script that does this, so I wrote one myself. I chose … Read the rest

Awesome Note + Google Drive


For a long time I’ve been looking for a note-taking app that:

1) is available as an iPhone/iPad app ✔

2) synchronizes to either my own server or Google Docs/Drive ✔

3) has a web interface

4) supports organization of notes in hierarchical folders

5) has “todo” functionality (creation and due dates) ✔

6) allows assignment of priorities ✔

This … Read the rest

Squeezebox and the new LastFM API


Since my last post about SqueezeScrobbler on my Squeezebox, I’ve enjoyed 3 years of LastFM listening on Squeezeboxes, Linux and Mac boxes, iPhones and iPads.

Well, this fall, LastFM announced that they would hit my listening pleasure with dual strikes: deprecation of the old API and discontinuation of the radio service in other countries than the US, UK and Germany. … Read the rest

Taking citizen cyberscience a step further

Citizen Science

Recently I’ve stumbled upon the terms citizen science and citizen cyberscience. The last term was apparently invented by Shuttleworth Fellow Francois Grey as a label for BOINC-based distributed computing projects like seti@home, folding@home and his own lhc@home. Grey is also behind the Citizen Cyberscience Centre in Geneva – on the web pages of which there’s more information to be … Read the rest

CERN School of Computing 2011 was… awesome


As exemplified on the pictures above (from the photo gallery of one of the students), CERN School of Computing includes a good deal of extracurricular activities. Which probably goes a long way in explaining the good and humorous atmosphere in the classroom.

Having spent a lot of energy preparing the exercise with the great CSC team, it really was great … Read the rest

The vision of GridFactory


In this post I’ll try to explain the vision behind a software suite I wrote at the Niels Bohr Institute, University of Copenhagen, 2009-11.

The ideas for the software arose from my dual involvement with the high energy physics and the e-science groups. Some of the code originated in previous projects, including distributed computing efforts of the ATLAS experiment at … Read the rest

Headweb on Boxee Beta


I’m quite happy with my small HTPC running Boxee on Ubuntu. The hardware is a Zotac Ion board with an Atom CPU and an Nvidia graphics card. Both software and hardware have their issues, but after enough hacking I’ve a setup that gets the job done wrt. watching movies off my file server. My main gripe has been the lack … Read the rest

CERN School of Computing 2011 – Exercise 2

In this exercise we’ll solve the same assignment as in exercise 1, but using a prepackaged GridPilot application.

  • Download and install GridPilot
  • Start GridPilot and answer the initial questions – enable only the computing system “GridFactory” and set the submission host to
  • Import the app “ttbar_exercise”
  • Select the application/dataset “ttbar_exercise-100k-events” and click “Run”
  • Select the application/dataset “ttbar_exercise-merge” and
  • Read the rest

CERN School of Computing 2011 – Exercise 1

pT diboson distribution.

pT diboson distribution.

This exercise was created for the 2011 CERN CERN School of Computing, hosted by the Niels Bohr Institute, University of Copenhagen.

Credits: physics content of this exercise by Jørgen Beck Hansen from the Niels Bohr Institute.

LHC Monte Carlo event generation and analysis


Generate 500’000 LHC t-tbar events with PYTHIA and analyze the data: find bosons … Read the rest