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Showing posts from February, 2016

Tax Season

Canada Tax Planning for the Middle Class Working class people need not do tax planning - they don’t have anything and don’t pay anything.  Rich people hire accountants to keep track of it all.  The rest of us, need to do tax planning. As Joe Walsh put it: I have a mansion, forget the price I've never been there, they tell me it's nice I live in hotels, I stare at the walls I have accountants who pay for it all.  The general solution to tax problems is to use corporate law to your advantage.  Corporate law changes very slowly and is fairly uniform across the world.  Large companies do not like it when governments touch corporate law, so politicians mostly keep their hands off it, since it can be political suicide.  Don't rely on Trusts.  Trust law is very hazy and therefore dangerous and changed for the worse recently, causing many tax problems. The worst thing is personal tax law - it changes with every budget, so it is hopeless to do long term planning for

Network Emulator

In my experience, it doesn't help telling developers that a radio data link is inherently slow and unreliable and that it gets worse with increasing distance.  They will always design for the best case - 1 meter of copper wire in a lab - and then be all upset when it doesn't work so well in reality. The solution is to make them a configurable network emulator from an old laptop PC (with a USB ethernet adaptor for a second port), put it between two of their machines and then stand back at a safe distance from any nerf guns or rubber band rifles and watch the wheels fall off the software. This network torture tool uses netem and bridge-utils to create a transparent bridge between two ethernet ports.  This cruel script is prettied up with Zenity , so that one can use sliders to vary the delay and packet loss. Either make the network utilities SUID root, or run the script as root. #! /bin/bash # Network Emulator # Version 0.1, Copyright GPL, Feb 2016, Herman Oosthuysen #

Mirror, Mirror on the Wall...

A Private Linux Mirror Debian/Ubuntu mirroring is also described down at the bottom - it is super simple. A Private Fedora Mirror If you need to replicate Fedora based machines, then you need to set up your own rpm file mirror.  This allows you to automate the whole install with Kickstart off your own server on a LAN and you can then freeze your server at arbitrary points to facilitate a production run of identical machines. The installation server can be an old laptop PC with a huge USB disk ( reformat the disk with gparted to ext4.  The file system must support UNIX permissions and links ).  The file server doesn't have to be very fast.  To do an install, you only need this server machine, a big switch and bunch of target machines with Kickstart ( ) and do a netboot , using DHCP and a web server such as lighttpd . To make your own mirro