This is the new home for Technical Musings, the technical blog I have maintained for a number of years. Virtually all the posts prior to 2022 were ported directly from the old github.io site. I also addd a bunch of news items (from my old personal website) that are now curated under the News category. While my old github.io blog will be perserved for posterity, all current/future updates will occur here.

NFS working on the Parallella

Phew! After a bit of effort, I was able to add an external hard drive to my parallella cluster, and make it accessible to all the nodes by mounting it on a NFS. I’ve updated the parallella cluster post to include this information. Visit it here to learn how to set up NFS on your parallella cluster too!

Get Wireless on the Parallella

I haven’t posted here in a while, mainly since I’ve been very busy with other things. Recently, I downloaded the updated image from Adapteva and started experimenting with it. Needless to say, the image that Parallella is now distributing is a LOT better than the one my students and I used last year during the course. For one thing, the new version of the kernel has support for wireless. Getting connecting to wireless is a cinch using the new image.

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Running JtR on our Parallella Beowulf Cluster

In the previous post, we created a Beowulf cluster using N Parallella boards. If you are using my images, the files you need to run the John the Ripper application should already be on them. If you don’t (or if they aren’t), follow this tutorial to set up the files on your cluster and get going. I’ll also walk you through how the code works. I wrote this demo for my parallel computing class, and presented it at the “Budget Beowulfs” special session at SIGCSE 2015.

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Creating a Parallella Cluster

The goal of this tutorial is to create a simple Beowulf cluster using Parallella boards. After completing these instructions, you should have a simple Parallella Cluster with N nodes. In the examples that follow, N=4. However, the tutorial can be used to create clusters of any size N. These instructions are adapted from the raspberry pi cluster instructions provided by Dr. Simon Cox from the University of Southampton. Unlike those instructions, I designed this tutorial to enable students to assemble a working parallella cluster within one hour.

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The Dot Product Program Revisited

Did you try and fix the Dot Product program from the last post? How successful were you? As you get used to Epiphany programs, it will get easier to debug and write your own. For now, it’s best that whenever you write your own programs, you always start from an existing Epiphany program and slowly make changes. Recall that we want to calculate the sum of products of two vectors containing the elements between $0 \ldots N-1$, for some value of $N$ (Assume $N$ is a power of 2, and $N \geq 16$.

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