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Car Computer Raspberry Pi 3 Upgrade

Raspberry Pi 3 upgrade for the Car Computer Recently I wrote about my car computer project based on the Raspberry Pi 2. The performance while acceptable in most situations, would drop and get noticeably sluggish during resource intensive activities such as processing large play queues or music directories. The free space around the [...]

By |March 7th, 2016|Hardware, Linux|9 Comments

Building a Raspberry Pi Car Computer

6 months ago I bought an 80 series Toyota Land Cruiser and the time since has been doing the car up in preparation for a trip around Australia. Since its release the 80 Series Land Cruiser has earned itself a reputation as a dependable and an almost unbeatable machine off road. But given the advances [...]

By |February 7th, 2016|Linux, web development|19 Comments

Changing the Linux Mint Login Background Images

Newer versions of Linux Mint use MintX as the default login screen greeter. By default it comes with a predefined collection of images that display in the background that change periodically in a slide show type format. The default images are great but I wanted to add a personal touch to my system and change [...]

By |February 1st, 2016|Linux|0 Comments

Raspberry Pi 2 Bitcoin Node

Not long ago I set up a Bitcoin node on a Debian Wheezy VPS to teach myself about Bitcoin and the blockchain in general. It was a great learning experience but the memory requirements of the Bitcoin software kept causing my VPS instance to run out of memory so the kernel would constantly be killing off the bitcoind process. A growing blockchain also meant the node was getting close to the limit of its available disk space as well. Simply increasing the amount of disk space available to the VPS instance with the plans offered by the hosting provider was going to be prohibitive for the purpose so I decided to assess other solutions. Luckily I had a spare Raspberry Pi 2 that I had yet to do anything with at home. So I made the decision to try and install a Bitcoin node on that instead to save some money. The main expense with using the Raspberry Pi was going to be finding enough storage for the block chain. I didn’t have an SD card that was big enough at home to¬†accommodate the operating system image and the block chain. So I opted to buy a cheap external USB flash drive to keep it separate from the root filesystem. After formatting with ext4 the flash drive has 57Gb of available space, at the time of writing the blockchain takes up 40Gb of space so that leaves a further 17Gb for future growth. Continue reading “Raspberry Pi 2 Bitcoin Node” »

By |May 26th, 2015|Hardware, Linux, Open Source|0 Comments

Running a Bitcoin Node on Debian Wheezy

Over the last few years I have keenly followed the rise of Bitcoin from its early days trading at around $8USD. I watched with interest when it made its sharp rise to $1200USD and then felt a bit of dismay with more recent decline back to around the $200USD mark. As a whole I think Bitcoin and the Blockchain are both game changing technologies that are yet to see their full potential. So over the last few months rather than just watching the Bitcoin exchange rate bounce around the place. I sought to get a deeper understanding of how the underlying technology works and how it can be extended further. As part of this learning process I decided to set up a Bitcoin node both to act as learning resource for myself and to help contribute something to the larger Bitcoin network. In this article I am going to run through the process of turning a VPS running Debian Wheezy into a fully fledged Bitcoin node. Continue reading “Running a Bitcoin Node on Debian Wheezy” »

By |January 22nd, 2015|Linux|0 Comments

Simple Iptables Blacklist

Anyone that has run a server for any length of time quickly learns that the Internet is full of spammers, bots and other characters you would prefer didn’t exist. A firewall is key to keeping these guys out and Linux comes with a Kernel level firewall called iptables that can be employed for this purpose. The only downside of iptables is that people who don’t deal with it on a regular basis tend to find its syntax a little bit daunting. In this post I am going to run you through the process of setting up a basic firewall IP blacklist. Using a bash script to read an blacklist of IP addresses and feeding these to iptables so they can no longer access your server. First up create decide where you would like the script to live. for this example I am just going to put it in /root/scripts. i.e mkdir /root/scripts nano firewall.sh Continue reading “Simple Iptables Blacklist” »

By |June 16th, 2014|Linux, Security, Uncategorized|0 Comments

Creating a Tor Relay on Debian

The TOR project has proven itself an important tool in the fight to protect the anonymity of people online. The project obviously needs servers to route traffic through for the project to achieve its goals though. So contributors are needed to donate relays nodes ensuring a free Internet for all. In this post I am going to run you though the process of installing TOR and configuring a relay service for use by the network on a Debian system. First up login to your machine via a terminal, update the package library and install the Tor server: apt-get update apt-get install tor Then change into the Tor config directory cd /etc/tor Continue reading “Creating a Tor Relay on Debian” »

By |June 12th, 2014|Linux, Security|0 Comments

PHP FPM Errors After Upgrade

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By |June 10th, 2014|PHP, Security, Sysadmin|0 Comments

Quick Intro To Memcached Stats

A few days ago I was given the job of changing the caching engine used in a Zend Framework based application from a simple flat file system based caching system to a memcached based object store that could be used by multiple servers. After extending the existing application bootstrap file to support the new cache [...]

By |May 19th, 2014|Programming, Sysadmin|0 Comments

Linux CLI: File Text Search & Replace

Occasionally you need to change the contents of some files easily to save a lot of manual work. In my case it was a server migration, the old IP address of a server was referred to from numerous DNS records. This meant the contents of a couple of hundred Bind zone files would also have to change so that they would reflect the new server address. This is task that would take way too long to do manually, luckily grep and sed can automate the process. In this post I will show you how to recursively search for and change a string in all files that exist below a directory. The format for doing a recursive search / replace looks like: grep -rl ‘search_term’ ./ | xargs sed -i ‘s/search_term/replacement_text/g’ Continue reading “Linux CLI: File Text Search & Replace” »

By |December 19th, 2013|Linux|0 Comments