The great thing about working with Linux is the constant, serendipitous, discovery of the "best" command line tool ever. This happened to me the other day when I discovered, possibly the best ever, command line utility for network diagnostics.

"mtr" a network diagnostic tool

The mtr utility investigates the network connection between the host that mtr runs on and a target machine. Essentially it is a dynamic traceroute that constantly updates, and shows, at which router your great bandwidth pipe, gets squeezed to a trickle with a calculated mean and standard deviation.

More times than I care to mention I find myself having to battle with libvirt taking over my iptables rules and starting its own instance of dnsmasq, which just ends up ruining my whole day. Libvirt is a great abstraction layer for virtualisation, and although its xml config format and command line interface are well documented, how it works under the hood is less so.

As a rule I prefer not to compile custom kernels on rpm and apt based distros unless absolutely necessary. If I know I am going to have to customise the kernel before hand, I prefer to use a source based distro such as Gentoo. That way there is nothing that gets in your way of the simple, make menuconfig=>make install=>make modules=>make modules_install=>mkinitrd (if necessary) recipe for success. Most times for debian and redhat based distros you can get by with just installing the kernel headers and then building your special module form there. 

Recently I have had to assist two friends with systems that were borked to the point of no longer being bootable. In both cases there had been warning signs that there was impending doom, like the machine spontaneously rebooting, or having to cold boot the laptop several times to get it to the windows login prompt.

Recently a group of Linux enthusiasts, including myself, founded a Linux User Group based in Randburg, Johannesburg. I gave a presentation on Linux virtualisation at the first meeting and we are planning to have our second on the 30 August 2007. Everyone is welcome from beginners to expert.