Recently in hardware Category

This post contains my notes - what I did to make it work properly, so next time I build the system, I have a step by step guide. In case you lived under the rock for the last months and don't know what Raspberry Pi is, you should visit www.raspberrypi.org now.

I bought Edimax EW-7811Un adapter for my Pi - small factor, b/g/n type, so why not... especially when vendor says it provides Linux drivers (wohoo!). Sadly as it turns out, compiling drivers on x86 or x64 and ARM architectures can be totally different experience - especially with Raspberry Pi being in it's software infancy. In all seriousness - Pi is for those that like to solve problems (at least at the current stage), but the community works hard to catch up very quickly - great stuff!

This time from the department of almost wasted time...

We all know that serial ports come very handy when you need to (re)configure something like a switch/server/firewall or similar device. In theory you can do that over TCP/IP nowadays with one hint - you need to have connectivity. All would be ok if not the fact that those very switches/firewalls you want to reconfigure actually provide the connectivity you need :-)

The Idea

Now... why spend hundreds of pounds/dollars on off-the shelf kit? Sure, it's cool, properly built and works unless you mess it up, but where's the fun part?! Today I needed a very very quick and cheap solution, so:

1. SheevaPlug - £114.00
2. 13-port USB hub - £19.99
   
3. USB-serial dongles (pl2303) - £14.99 each

This way I have fully networked console server with 4 ports just under £200 - acceptable, especially when the whole thing is running off DHCP and calls home via OpenVPN - very easy to deploy!

Tricky bits

Generic Sheeva has one USB host port and hub has 13 of them - I want to send it off to remote location and have somebody plug it in and not mess up what's where. Trick is to write appropriate udev rules to detect adapters and give them ttyUSBn names according to physical port on the hub.

All would be fine and easy if it worked as documented - sadly it doesn't. First problem was that ATTRS{devpath} (as returned by udevadm info --attribute-walk -n /dev/ttyUSBn that allows to distinguish usb ports) was used by rule in tests but wasn't propagated properly on none of my Debian or Ubuntu boxes. Then I tried to match KERNELS for parent devices - nope... if you go too far up the tree it doesn't see s**t :-/

Recently I had some serious problems with wi-fi at home - especially one of the laptops was dropping off and couldn't come back. Quick survey using Kismet and other tools to scan what's flying around has proven that my network is in less populated part of the spectrum (at least here) but still, problems are getting worse and worse.

I was fully aware of Wi-Spy by Metageek, seen it in action previously but never had a chance to buy one. Part of the decision was the price back then, maybe now it would be another game, but anyway - I got myself another device, made by well known wi-fi vendor Ubiquiti and it's called AirView2.



What's so special about this one? Why it's better than Wi-Spy?

First of all I didn't say it's better. It's different, woks with Linux, Mac OS X and Windows, has a nice price tag and does pretty much the same as Wi-Spy. Let's have a closer look then, shall we?

Some time ago (rather long long time ago) we have decided to purchase some small device to turn it into very portable server, that we could send to one of our friends to host. The whole purpose was to get Nagios on it and to monitor our sites from outside of our networks. To some people it may sound crazy, but it makes kind of sense - how many times you have heard from someone "it works on my computer"? Too many times?

The goal is to know when my (and possibly why) visitors/customers can't reach my servers and to be able to diagnose if that is local to some location or network part or it affects wider audience. Up to some point remote sensor answers that question - at least from a perspective of his particular location.

After looking around the net we've decided to get one of those famous Soekris kits.


Was it a good choice as a hardware platform? How will it scale when the amount of monitored systems will reach certain level? Let's see where it got us so far as the system is live for about a year now.