Category Archives: Linux

Linux and Open Source

LCA2008 – Day 0!

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Well today was Day 0 of LCA2008 and I was there as a volunteer helping out with lugging things, putting banners up, folding shirts and working on the registration (( rego, in Australian )) desk.

I’ve also started uploading my photos from this to Flickr and it looks like I’m the first to do that (or at least tag them as such). 🙂

Day 1 registration opens at 8am and I’m going to do my best to be there early (Connex permitting)!

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!

Linux ulimit memory enforcement oddity

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Found an interesting wrinkle in the Linux handling of ulimits for maximum memory size and data segment size – they are not enforced by current glibc / kernel configurations in certain conditions.

I tracked this down to the fact that somewhere around glibc 2.3 the malloc() implementation was ripped out and replaced with one that uses mmap() for allocations of 128KB or more. The kicker is that the kernel mmap() implementation only cares about the virtual memory ulimit (RLIMIT_AS) for enforcement, the others are just ignored!

So currently an application which uses small allocations (<128KB) will find malloc() failing when they hit their max mem / data seg size ulimit whereas an application that grabs RAM in larger chunks will sail happily past that without a care in the world..

Bug, feature or undefined behaviour ? You decide.. 🙂

Installing Lacie 4L Lightscribe software on AMD64 Ubuntu/Debian systems (Updated x3)

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Caveat: Whilst the below works for me for those particular applications you may find that other 32-bit only applications require a fuller 32-bit environment, which you can get using a separate install of a 32-bit Ubuntu (often called a “chrooted environment”) – please see the corresponding Ubuntu Wiki page for more information.

I have a new AMD64 compatible system (an Intel quad core box) which comes with an ASUS DRW-1814BLT Lightscribe DVD burner. Problem is that I’m running a 64-bit version of KUbuntu Linux (as it’ll have 8GB RAM once the final sticks arrive) and the closed source Lightscribe software is 32-bit only and won’t install without a bit of prodding.

So, to help others, this is the hack that I did to install it successfully.

First I had previously installed the 32-bit compatibility libraries for AMD64 thus:

$ sudo apt-get install ia32-libs

Then I downloaded the Lightscribe System Software as a 32-bit .deb and the Lacie 4L package (which has a nice GUI) as the x586 RPM.

Then I installed fakeroot and alien and converted both of them to TAR files thus:

$ fakeroot alien -t lightscribe-1.10.19.1-linux-2.6-intel.deb
$ fakeroot alien -t 4L-1.0-r6.i586.rpm

Then I converted the two tar files straight back into .deb’s:

$ fakeroot alien lightscribe-1.10.19.1.tgz
$ fakeroot alien 4L-1.0.tgz

Then it’s the usual installation procedure of:

$ sudo dpkg -i ./lightscribe_1.10.19.1-2_all.deb
$ sudo dpkg -i 4l_1.0-2_all.deb

and it seems to work (though I have no Lightscribe media to test with yet!):

$ 4L-cli enumerate
Using /etc/lightscribe.rc
Drive path: /dev/sr0
Usable: 1
Full name: ASUS DRW-1814BLT 1.13 132
Model: DRW-1814BLT
Manufacturer: ASUS
Capabilities: monochrome
Drive inner radius: 21700
Drive outer radius: 58700

Update: I’ve since spotted that dpkg has a –force-architecture option, this may avoid the need for converting the lightscribe package.

Update 2: It works! I’ve successfully used the GUI to label a CD as a test.

Update 3: Paul Bailey has distilled the above into a simple recipe.

Microsoft – put up or shut up

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So Steve Balmer said:

for the appropriate fee Novell customers also get essentially the right to use our patented intellectual property. And I think it’s great the way Novell stepped up to kind of say intellectual property matters. People use Red hat, at least with respect to *our* intellectual property in a sense have an obligation to eventually compensate us.

Now, Mr Balmer, precisely what “patented intellectual property” are you talking about here ? Please be specific, patent numbers would be very handy..

Or are you just trying on a shakedown with vague threats to see what easy protection money may come your way now that Vista and Office 2007 aren’t selling so well ?

Thanks Novell, for nothing..

Emerging Linux Filesystems talk – LUV October meeting – 2nd October 2007

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Recently LinuxWorld commissioned me to write an article on Emerging Linux Filesystems (the formatting is a bit different from the original I sent, but the slideshow of graphs now works) and have kindly given me permission to present a talk based on my work at the October Linux Users of Victoria (LUV) meeting.

So if you can make it you can hear about my experiences with ChunkFS, btrfs, NILFS, ext4, Reiser4 and ZFS/FUSE, as well as with ZFS under OpenSolaris (in this case Nexenta).

I’d also like to thank Dragan at Xenon Systems for the loan of a shiny, Linux friendly, test system!

SCO files for Chapter 11 Bankruptcy Protection

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From Groklaw:

Here’s the title of the press release: “The SCO Group Files Chapter 11 to Protect Assets as It Addresses Potential Financial and Legal Challenges”, which you can find here. They say reorganization “ensures business as usual.”

It may also act as a useful extra delaying tactic in the determination of how much they owe Novell in their trial..

Some of SCO’s remaining claims were yet to be decided at trial, which was to begin Sept. 17. The trial will be stayed under bankruptcy law, according to Novell public relations director Bruce Lowry. “We’ll be looking at our options,” he said.