If you're interested in ways to back up stuff, and haven't tried Dar yet, here's an article on using Dar that I've just published on my personal blog. In short, Dar works very much like Tar, but it's got a built-in feature for slicing up archive files which comes handy when you want to distribute backup files across several media, for example DVDs or hard disks.

Monty Widenius dissects MySQL’s dual license. Intuit moves to the EPL. And more.

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“Tracking the open source news wires, so you don’t have to.”

# Monty Widenius blogged about the apparent changes to the dual licensing of MySQL.

# Intuit announced that its code.intuit.com will be moving from CPL to EPL.

# Matt Asay asked whether Google’s open source advocacy might be a scheme to lower the value of patents.

# Vision Mobile’s Andreas Constantinou explained the differences between open source …

As well as contributing to the CAOS research practice here at The 451 Group I am also part of the information management team, with a focus on databases, data caching, CEP, and - from the start of this year - data warehousing.

I’ve covered data warehousing before but taking a fresh look at this space in recent months it’s been fascinating to see the variety of technologies and strategies that vendors are applying to the data warehousing problem. It’s also been interesting to compare the role that open source has played in the data warehousing market, compared to the database market.

I’m preparing a major report on the data warehousing sector, for publication in the next couple of months. What follows is a rough outline of the role open source has played in the sector. Any comments or corrections much appreciated:

Unlike other …

I'm happy to announce that the schedule for OpenSQL Camp 2009 (European Edition) has been published on the FrOSCon timetable now. We have a great selection of topics and speakers, so don't miss it! OpenSQL Camp is a subconference of FrOSCon, the Free and Open Source Conference, which will take place on August 22nd and 23rd in St. Augustin, Germany.

The admission fee for the entire conference (both days, incl. OpenSQL Camp) is 5 EUR, you can pre-register here until August 10th (and if you do so today, you will still get a free T-Shirt as well!). Of course, you …

OIN offers cash for patents. CentOS crisis averted. Microsoft denies GPL violation. And more.

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“Tracking the open source news wires, so you don’t have to.”

# Open Invention Network offered individual inventors cash for patents, and acquired patents from V_Graph.

# The H Open reported that the management problems at CentOS are now resolved.

# Sam Ramji told Network World in detail why Microsoft believes its Linux IC code did not violate the GPL (from 15m 30s).

# Canonical delivered an on-premise version of …

When open source goes bad. Is open source a success or failure? And more.

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“Tracking the open source news wires, so you don’t have to.”

When open source goes bad
The H reported on the apparent turmoil at the CentOS project, while Jay Lyman offered the CAOS perspective. Meanwhile Slashdot reported that Alan Cox has quit as Linux TTY subsystem maintainer.

Success or failure?
Danny Windham, Digium CEO, …

I was actually exploring inotify-tools for something else, but they can also be handy for seeing what goes on below a mysqld process. inotify hooks into the filesystem handlers, and sees which files are accessed. You can then set triggers, or just display a tally over a certain period.

It has been a standard Linux kernel module since 2.6.13 (2005, wow that’s a long time ago already) and can be used through calls or the inotify-tools (commandline). So with the instrumentation already in the kernel, apt-get install inotify-tools is all you need to get started.

# inotifywatch -v -t 20 -r /var/lib/mysql/* /var/lib/mysql/zabbix/*
Establishing watches...
Setting up watch(es) on /var/lib/mysql/mysql/user.frm
OK, /var/lib/mysql/mysql/user.frm is now being watched.
[...]
Total of 212 watches.
Finished establishing watches, now collecting …

Intuit launches open source project. SFLC on Microsoft GPL violation accusations.

Follow 451 CAOS Links live @caostheory on Twitter and Identi.ca
“Tracking the open source news wires, so you don’t have to.”

# Intuit launched open source projects and community to develop apps based on its Intuit Partner Platform, while Savio Rodrigues declared Intuit’s open source play is all business.

# SFLC’s Bradley Kuhn told SDTimes Microsoft was in violation of the GPL.

# MySQL and Memcached-based appliance vendor Schooner Info Tech has raised $20m in Series B funding.

# …

iostat -x is very useful to check disk i/o activities. Sometimes it is said that "check %util is less than 100%" or "check svctm is less than 50ms", but please do not fully trust these numbers. For example, the following two cases (DBT-2 load on MySQL) used same disks (two HDD disks, RAID1) and reached almost 100% util, but performance numbers were very different (no.2 was about twice as fast as no.1).

# iostat -xm 10
avg-cpu:  %user   %nice %system %iowait  %steal   %idle
       21.16    0.00    6.14   29.77    0.00   42.93

Device: rqm/s   wrqm/s   r/s   w/s    rMB/s    wMB/s
sdb    2.60 389.01  283.12 47.35     4.86     2.19
avgrq-sz avgqu-sz   await  svctm  %util
43.67     4.89   14.76   3.02  99.83

# iostat -xm 10
avg-cpu:  %user   %nice %system %iowait  %steal   %idle
       40.03    0.00   16.51   16.52    0.00   26.94

Device:         rrqm/s   wrqm/s   r/s …

Gearman is an open source generic framework for distributed processing. At OSCON 2009 I attended the Gearman: Build Your Own Distributed Platform in 3 Hours tutorial.

While it’s very easy to install Gearman, and follow the first example, if you missed the all important additional PHP steps listed on just one slide you may be left with the “‘Class ‘GearmanClient’ not found” error.

The following are detailed instructions for the installation and configuration of Gearman and PHP on Ubuntu 9.04 Jaunty.

Add the Drizzle PPA to get pre-packaged versions of Gearman.

cp /etc/apt/sources.list /etc/apt/sources.list.orig
echo "deb http://ppa.launchpad.net/drizzle-developers/ppa/ubuntu intrepid main
deb-src http://ppa.launchpad.net/drizzle-developers/ppa/ubuntu intrepid main" …