Author Archives: Chris Samuel

KDE 4.0.0 is released!

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So the announcement is up on the KDE website, Kubuntu has announced its packages and for the past week or so I’ve been running KUbuntu Hardy Heron (currently in alpha, will be 8.04) with it installed and trialing it with a “kde4” test user!

Not bad actually, the final release seems like a massive improvement over earlier versions and I’m not running into the killer bugs that I found previously (to much relief!). The new desktop effects in KDE4 work well with this Intel G33 graphics card (once I’d dropped the Xorg acceleration method back to the old XAA from EXA) and I must admit to being sorely tempted to try it out as my main desktop. I think I might create yet another user for that an experiment first though with a copy of my .kde files.. 🙂

Sears – purveyors of Spyware to the masses ?

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I wonder how many people using Windows have been bitten by this new spyware, as related by the Computer Associates Security Advisor Blog ?

Sears.com is distributing spyware that tracks all your Internet usage – including banking logins, email, and all other forms of Internet usage – all in the name of “community participation.” Every website visitor that joins the Sears community installs software that acts as a proxy to every web transaction made on the compromised computer. In other words, if you have installed Sears software (“the proxy”) on your system, all data transmitted to and from your system will be intercepted.

The mention of “banking logins” is to get your attention, because as this apparently hoovers up all your traffic it will get whatever you do, presumably including credit cards, etc.

They also have an interesting take on how to do privacy policies:

What I have come to learn is that if you navigate to http://www.myshccommunity.com/Privacy.aspx you could actually get one of two policies. […] If you access that URL with a machine compromised by the Sears proxy software, you will get the policy with direct language (like “monitors all Internet behavior”). If you access the policy using an uncompromised system, you will get the toned down version (like “provide superior service”). Both policies share the same URL and same look and feel – coloring, page layout, Kmart and Sears branding, etc.

In other words they have a policy that implies that it’s inoccuous prior to installation, which then springs into sharp relief once you’ve crossed the Rubicon and installed their spyware – nice touch!

(Via Bruce Schneier)

SMP implementation of bzip2

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Here’s something of a find, courtesy of Jordan Mendler on the ZFS/FUSE mailing list, an SMP implementation of bzip2 called pbzip2 by Jeff Gilchrist:

PBZIP2 is a parallel implementation of the bzip2 block-sorting file compressor that uses pthreads and achieves near-linear speedup on SMP machines. The output of this version is fully compatible with bzip2 v1.0.2 or newer (ie: anything compressed with pbzip2 can be decompressed with bzip2). PBZIP2 should work on any system that has a pthreads compatible C++ compiler (such as gcc). It has been tested on: Linux, Windows (cygwin & MinGW), Solaris, Tru64/OSF1, HP-UX, and Irix.

It’s packaged in Ubuntu (in Universe) and testing on this quad core Intel box (2.4GHz with 4GB RAM) on a 712MB tar file in comparison with the standard bzip2 showed pretty impressive performance!

Standard bzip2 compression:

chris@quad:/tmp$ time bzip2 -v backup-20020122.tar
backup-20020122.tar: 1.531:1, 5.227 bits/byte, 34.66% saved, 746250240 in, 487572628 out.

real 2m32.331s
user 2m29.593s
sys 0m0.976s

Standard bzip2 decompression:

chris@quad:/tmp$ time bunzip2 -v backup-20020122.tar.bz2
backup-20020122.tar.bz2: done

real 0m56.215s
user 0m54.519s
sys 0m1.136s

Parallel bzip2 compression:

chris@quad:/tmp$ time pbzip2 -v backup-20020122.tar
Parallel BZIP2 v1.0.1 - by: Jeff Gilchrist [http://compression.ca]
[Mar. 20, 2007] (uses libbzip2 by Julian Seward)

# CPUs: 4
BWT Block Size: 900k
File Block Size: 900k
-------------------------------------------
File #: 1 of 1
Input Name: backup-20020122.tar
Output Name: backup-20020122.tar.bz2

Input Size: 746250240 bytes
Compressing data...
Output Size: 487531723 bytes
-------------------------------------------

Wall Clock: 41.335455 seconds

real 0m41.338s
user 2m40.962s
sys 0m2.248s

Parallel bzip2 decompression:

time pbzip2 -v -d backup-20020122.tar.bz2
Parallel BZIP2 v1.0.1 - by: Jeff Gilchrist [http://compression.ca]
[Mar. 20, 2007] (uses libbzip2 by Julian Seward)

# CPUs: 4
-------------------------------------------
File #: 1 of 1
Input Name: backup-20020122.tar.bz2
Output Name: backup-20020122.tar

BWT Block Size: 900k
Input Size: 487531723 bytes
Decompressing data...
Output Size: 746250240 bytes
-------------------------------------------

Wall Clock: 18.078961 seconds

real 0m18.081s
user 1m3.516s
sys 0m1.776s

So that’s almost a x3.7 speedup over the single CPU version, not bad!

Oh, and yes, there is an MPI version available too, called mpibzip2.. 🙂

Taking the plunge (updated)

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I’m about to try and upgrade this blog from WordPress 2.0.11 to 2.3.2, expect breakage for a while!

Updated

That was quick (as ever) – I’m now running 2.3.2 – now for the plugins..

OK – plugins done and theme hacked to do a better job at being a variable width theme!

I’m going to be an Aussie! (Updated)

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Catching up on my backlog – a few weeks ago I received a letter saying:

13th December 2007

Dear Mr Samuel

On behalf of the Government and the people of Australia, I am delighted to advise that your application for Australian citizenship has been approved.

Yay! I’m going to be an Aussie (( well, OK, to be precise, a dual-national UK/Aussie ))!

Back in the middle of the year I decided that after having lived in Australia for almost 5 years it was about time to do the right thing and apply to be a citizen of my new home. I was hoping to get to vote in the 2007 general election, but changes in the process and travelling overseas meant that the interview that should have happened in September didn’t occur until the 7th December. So they moved pretty quickly from that to the approval! 🙂

I am still a PR (permanent resident) until I do the “Pledge of commitment” which will be some time in the next 6 months or so, but once that happens my PR visa will cease and I’ll need to get an Aussie passport to go with my UK one.

Update: Turns out that “in the next 6 months or so” is actually going to be this coming Australia Day, January 26th!

The Date of Christmas

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Some folks wonder why Christmas is on December 25th given there is absolutely no clue in the bible, so here’s a handy passage from Professor Ron Hutton’s (( Wikipedia entry )) excellent book “The Stations of the Sun” quoting the Scriptor Syrus, a Christian writer in the late 300’s CE:

It was a custom of the pagans to celebrate on the same 25 December the birthday of the Sun, at which they kindled lights in token of festivity. In these solemnities and revelries the Christians also took part. Accordingly when the doctors of the Church perceived that the Christians had a leaning to this festival, they took counsel and resolved that the true Nativity should be solemnized on that day

Now 354 CE is the earliest calendar (that of Philocalus) which gives that date, but Prof. Hutton goes on to point out that the pagan festival that Syrus mentions was just 80 years old then, hardly an ancient practice. He says:

It had apparently been decreed only in 274 CE, by the emperor Aurelian, as a major holy day of a new and syncretic state cult with the sun as its official chief deity.

This in turn was built upon the older Syrian “Unconquered Sun” cult, which had its major festival in late summer. I suppose that last bit makes it almost appropriate for Australia. 🙂

Electronic voting report in Ohio

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Ohio has published a report on an investigation into electronic voting machines, Wired reports on it, summarising one particular finding thus:

They found that a voter or poll worker with a Palm Pilot and no more than a minute’s access to a voting machine could surreptitiously re-calibrate the touch-screen so that it would prevent voters from voting for specific candidates or cause the machine to secretly record a voter’s vote for a different candidate than the one the voter chose. Access to the screen calibration function requires no password, and the attacker’s actions, the researchers say, would be indistinguishable from the normal behavior of a voter in front of a machine or of a pollworker starting up a machine in the morning.

…and if you think that’s bad enough, then here’s an interesting comment from a collection of complaints about voting in Florida in 2006 that were assembled after an FOI request:

Vote for one candidate registered as vote for different candidate

Upon opening ballot for first time voter saw “x” by Katherine Harris’s name though voter had not touched screen yet.

So the machines are quite capable of getting things wrong without a malicious attack (well, assuming that wasn’t the cause in the above events).

So, who would you like to win today ?

(Via Bruce Schneier)

Happy Yule/Xmas/Solstice/etc..

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Condiments of the seasoning to all!

Donna and I have been flat out recently (still are I guess given it’s gone 1am and we’re both still up!), which is why things have been so quiet here.. Still, we’re both doing well and very much appreciating all the rain we’ve had, the garden is loving it!

I’m dreaming of a wet Christmas…

Emerging Linux Filesystems

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In July I was commissioned to write an article for LinuxWorld called “Emerging Linux Filesystems” which they published in early September in three parts. Part of the deal was that there was a 90 day exclusivity period for them before I could republish it elsewhere, which has now lapsed.

So you can now read the article in its original (single page) form complete with inline images and graphs and covering Ext4, NILFS, btrfs, Reiser4, ChunkFS and ZFS under both FUSE on Linux and OpenSolaris. Enjoy!

My thanks to Don Marti of LinuxWorld for commissioning (and paying for) the article and to Dragan Dimitrovici of Xenon Systems for the loan of the test system!