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How to Start Learning Linux

I was asked for advice on how to start learning Linux. Rather than replying via email I’m writing a blog post for future people who ask such questions and also to get comments from other people which may provide information I missed.

Join a LUG

The best thing to do is to start by joining [...]

Timing Processes

One thing that happens periodically is that I start a process from an interactive shell, discover that it takes longer than expected, and then want to know how long it took. Basically it’s a retrospective need to have run “time whatever” that I discover after the process has been running for long enough that I [...]

Flash, Apple, and Linux

Steve Jobs has published an interesting article about Flash [1]. He criticises Flash for being proprietary, this seems a little hypocritical coming from Apple (who’s the only competitor for Microsoft in terms of being the most proprietary computer company) but is in fact correct. Steve advocates HTML5 which is a better technical solution to a [...]

Marshmallow Challenge for Linux Programmers

Tom Wujec gave an interesting TED talk about training people in team-work and engineering through building the tallest possible structures from 20 pieces of spaghetti, 1 yard of string, and 1 yard of sticky-tape with a time limit of 18 minutes [1]. The project is completed by groups of four people – which is probably [...]

Discovering OS Bugs and Using Snapshots

I’m running Debian/Unstable on an EeePC 701, I’ve got an SD card for /home etc but the root filesystem is on the internal 4G flash storage which doesn’t have much spare space (I’ve got a full software development environment, GCC, debuggers, etc as well as running KDE4). On some of my systems I’ve started the [...]

Ext4 and Debian/Lenny

I want to use the Ext4 filesystem on Xen DomUs. The reason for this is that the problem of fsck times on ext4 (as described in my previous post about Ext4 [1]) is compounded if you have multiple DomUs running fsck at the same time.

One issue that makes this difficult is the fact that [...]

Ext4 and RHEL5/CentOS5

I have just noticed that Red Hat added Ext4 support to RHEL-5 in kernel 2.6.18-110.el5. They also added a new package named e4fsprogs (a break from the e2fsprogs name that has been used for so long). Hopefully they will use a single package for utilities for Ext2/3/4 filesystems in RHEL-6 and not continue this package [...]

The Transition to Ext4

I’ve been investigating the Ext4 filesystem [1].

The main factor that is driving me to Ext4 at the moment is fsck times. I have some systems running Ext3 on large filesystems which I need to extend. In most cases Ext3 filesystems have large numbers of Inodes free because the relationship between the number of Inodes [...]

Finding Thread-unsafe Code

One problem that I have had on a number of occasions when developing Unix software is libraries that use non-reentrant code which are called from threaded programs. For example if a function such as strtok() is used which is implemented with a static variable to allow subsequent calls to operate on the same string then [...]

Per-process Namespaces – pam-namespace

Mike writes about his work in using namespaces on Linux [1]. In 2006 I presented a paper titled “Polyinstantiation of directories in an SE Linux system” about this at the SAGE-AU conference [2].

Newer versions of the code in question has been included in Debian/Lenny. So if you want to use namespaces for a login [...]