ESXi is popular hypervisor product from VMware. It comes with several management GUIs including Vsphere and VCenter. Command line tools are also bundled, though they are used more rarely. This article describes a short script to list all virtual machines on the system.
The script is below. It is intended to run under the Busybox shell, the default environment when you ssh directly into the system hosting ESXi. Continue reading →
This article presents a few informal benchmarks comparing the Raspberry Pi to the Raspberry Pi 2. The original Pi has a single core ARM v6 processor. The Pi 2 is quad core, ARM v7, and clocked faster than the Pi 1. But is it really six times as fast, as the makers claim ? Short answer: yes it is. And then some. Continue reading →
The Raspberry Pi’s low power consumption makes it well suited to the role of always-on server. This post describes how to install Owncloud onto the Pi. Owncloud is an open source software package providing remote file sharing services, similar to Dropbox. But with Owncloud, you retain ownership, security and control of the shared data.
My Raspberry Pi 2 was purchased from RS Components in the UK. It was installed with Raspbian (Debian 7) by applying the image “2015-01-31-raspbian.-wheezy.zip” downloaded from the raspberrypi.org downloads page. The following procedure was then performed without any further pre-work (other than enabling ssh in the basic setup). Continue reading →
Here is a tip for speeding up WordPress, especially if you are running it on a low power server. I made the change to WordPress running on a small ARM server, resulting in an immediate and dramatic speed up. It works because it prevents bots on the Internet from wasting your server resources. Continue reading →
This article explains how to send email from the Raspberry Pi. It is a generic procedure and also works on other Debian distributions. This is not for receiving mail, only for sending it. (Receiving email on the Pi is a much more involved process, requiring your Pi to preform the role of a full mail server).
The ability to send mail across the internet is useful. It enables your scripts and applications to send you email about system events or sending data such as pictures from a webcam. Continue reading →
This article discusses some of the caption and border effects available with the ImageMagick image processing package. ImageMagick is freely available for Linux and Windows. It offers a huge number of image processing options, so many in fact, that using the program can be a little tricky.
The following examples were evolved from the ImageMagick online documentation, plus a good deal of trial and error to get the details right. I used Linux, but the same commands should work under Windows. Continue reading →
The Raspberry Pi is a small Linux computer designed to help children learn programming. Being a full Linux System, it can also be used as a server or as the basis for various projects. The Pi’s low power consumption makes it particularly suited to the role of always-on web server.
This post describes how to create a simple photo gallery on the Pi, which can be shared over the internet with or without password protection. While not as polished as Flickr, Smugmug or similar services, it allows you to retain ownetship, control and security of the shared images. Continue reading →
Solaris administrators may have seen the message “Catastrophic file error – zero length” in their system logs. Although it sounds serious, there is nothing “catastrophic” about it. This post explains how to stop the message from flooding your log files. Continue reading →
Here is a quick fix that might help users experiencing the “no devices available” problem when using xsane, the Linux scanning tool.
In this case, the device was an HP 3070 B611, a combined printer and scanner. The OS (Fedora 20) was able to see the device as a printer and print okay, but the scanner part did not work. Xsane just popped a small window saying unable to find device.
The fix was a change in the CUPS configuration, and it may therefore work with other versions of Linux. Continue reading →
BT is a popular internet service provider in the UK. BT subscribers receive a free router called the “BT Home Hub“. A new model of Hub is launched every few years, and as BT never takes the old ones back, many people have a old Hub tucked away somewhere, gathering dust.
This post explains how to convert an old Home Hub 1.0 into a second wireless access point (“AP”) on your network, strengthening and extending the wireless signal around your home or office. Although the details are for that router, the basic procedure should work for other BT and perhaps non-BT routers. Continue reading →