Monthly Archives: December 2008

Open Source Virtualization with VirtualBox

There are many technologies which I am very much on top of because I use them on a regular basis, here are others that I interact with periodically and it’s enough to stay abreast of developments and do basic troubleshooting but from time to time there are technologies that I’m only peripherally aware of and have only a basic understanding of. One such technology is virtualization or virtual machine software.

For almost ten years I’ve been hearing about software like that made by VMware which allows for a virtual computer to run inside of a host operating system. To this day I haven’t done anything more with this type of software than to fire it up and see that indeed it does work. It’s not that I don’t see the advantages, it’s just that I haven’t personally encountered a situation where I can justify the time and effort it would take to set it up. That said I do like to know what’s going on in all areas of technology and what I’ve been hearing lately is some movement in the open source virtualization arena.

For some years now I’ve known about some projects such as Xen, Bochs and QEMU. The problem with these solutions is they are really not open source replacements for commercial virtual machine software like VMware. I’ve heard great things about Xen and it’s ability to virtualize Linux systems (on Linux systems). While this is valuable in many cases it’s not for most of what I want to do which is to run a guest OS on an entirely different host OS. Bochs is more on target but this is an effort to emulate the x86 platform enitrely in software, a bit heavy duty (and with significant speed costs) for what I normally would want to do which would be to run an x86 guest OS on an x86 host, for example a Windows guest on a Linux host. QEMU has the upper hand here. While it’s still a big heavy emulator there is some closed source accelerator code which can help in x86 on x86 situations. Of course the closed source part is a bit of a drag. Still the real problem with all of these is that they are incredibly more difficult to configure (and especially to configure and setup a new guest OS on) than their commercial counterparts.

Well, the world may be changing. What I’ve been hearing recently is that an open source project from Sun called VirtualBox is looking like it will give some of the commercial vendors a run for their money (so to speak). There is no doubt that VirtualBox is still in the early stages of life but the development team seems to be putting some real effort into it and new releases have been timely. I’ll be excited to follow the continual development of this product.

The Use of S3 and EC2 for Remote Backup

Even before the introduction of the Amazon S3 storage service I was intrigued bye the possibilities of secure backup over the Internet. Over the years I’ve evaluated a number of possibilities such as the use of rsync and Unison either to my own remote servers or to a service. I’m really not too interested in the commercial vendors as most of their software works on Windows or maybe Mac and my files reside on a Linux fileserver. It only makes sense that my backup solution should run on the Linux server as well.

None of these solutions seemed to quite fit the bill for me because of expense, concerns about data security or speed. Since the introduction of S3 I have started playing around with some of the scripts and software which have been developed to take advantage of these powerful services. I was still disappointed though mostly because of some data encryption concerns (on the storage system, not in transit) and the potential charges associated with backing up data to the S3 service. Ideally I would want something rsync like which would only transfer the changed parts of the files instead of recopying the entire file or directory. Unfortunately there is no built in support for anything like this in the low-level S3 system. So after playing with many scripts that suggested they would be able to do something along these lines and remaining unimpressed I decided to put things on hold for a while longer.

Eventually Amazon released the EC2 cloud computing platform but that still didn’t seem particularly useful for my purposes because of the lack of persistent storage between sessions. Once the elastic block storage became available things got more interesting. Now that I could retain data between sessions I had visions of a backup script which would launch an EC2 instance, mount an EBS volume and run rsync or Unison to backup directories on my local server to the remote site. I started playing around with EC2 and soon discovered that although it is very powerful it is a monster to control unless you are writing your own application from the ground up. For a simple job like this that should be easily accomplished by a script it can be a nightmare with several shell variables to set and paths to keep straight. Never mind the several encryption keys and the changing SSH host identifier to deal with. Eventually with some help from two fantastic blog entries (Ereblog and Free Wisdom Online) I was able to get something working…mostly.

It’s quite a fragile thing and you have to make sure that things are executed in the correct paths and with the correct environment variables set. In addition the returned data from the control commands is just awked from the output so it could easily break if the control package were updated, etc. The final nails in the coffin for me were my increased backup storage requirements for photos, audio and video which are huge and can change the economics of doing remote backup quickly. Even for a slimmed down set of documents I found the process to be too slow and fragile for my needs. In the end I have gone back to hauling hard drives with data backups off site and using the rsync program locally to sync these periodically with my live storage.

*Edited 2/2/09 to fix the several times I mistakenly called EC2 EC3 although I knew better. Thanks to the commenter for pointing this out!

Remembering our Media Past

One of my more recent pastimes when I have a few minutes to spare and am already caught up on the news and either need to relax and unwind a bit or just don’t have time to dive in to a more substantial project is to browse around on YouTube (similar to I do on Wikipedia) and see what turns up. One of the more interesting things that I have turned up are old “airchecks” from Twin Cities area television stations.

Being a media geek I’m fascinated by how news has changed over the years, particularly in my market. I’ve known about many of the private collectors of radio airchecks for some time but thanks to the fine people at there are now many TV airchecks from the area available online as well. Some of my favorites are actually the tv news reports on some of the area radio stations (which is how I found the archive in the first place). It’s amazing to see just how different news reporting looked even 15 years ago. While we can discuss somewhat about whether the content is any better there is no doubt that the production quality has drastically improved.

The Coldplay/Satriani Issue

If you’re not yet familiar with the Coldplay/Satriani issue the basic premise is that guitar artist Joe Satriani is suing the band Coldplay because he believes that a member of the band who attended one of his concerts copied some of his music and used it in one of their songs. We’re not talking about sampling or copying a part of a recording but actually copying the musical thought behind one part of the song. In any event you can get a brief idea of what I mean by watching one of the many videos on YouTube where they play the two sections one right after the other. To further complicate things it seems the original idea may have come from a third artist.

Being a bit of a music geek and copyright activist I find this all rather fascinating. After all there a a limited number of original chord progressions. My personal feeling is that you should not be able to own a chord progression at all. Music is built collectively over time by different artists listening to and learning from one another, it’s just how it works. In classical and solo piano music we have this as “variations on…” and the entire development of the Jazz genre is about artists hearing each others “sound” and tweaking it.

I would argue that allowing ownership of chord progressions is similar to allowing ownership of the writing concept that “the butler did it” or one of the many standard plots found in movies and TV. This is plain silly and should not be allowed. Clearly, despite having similar sections and feelings, they are different songs (they are not identical). While it is nice, courteous and polite to acknowledge your inspirations it should not be legally required, nor should you be required to get permission nor should you have to pay for these rights.

Much of the YouTube coverage of this is the simple laying of one track over (or next) to the other. If you’re interested in a much more in depth look at the music theory of chord progressions and knowing how the to melodies and harmonies relate to each other I highly recommend looking at the two part series on the music theory behind the accusations put together by the Creative Guitar Studio in Canada, which also has an accompanying web site.

Change In Site URL

In an effort to make the articles on this site slightly easier for people to find and for me to be able to easily give the site URL to people verbally I have moved the blog portion of my site to it’s own URL, Thanks to the magic of mod_rewrite all of the old URLs should redirect to the new site. I don’t guarantee this will be the case forever though so if you are linking to any pages on the blog please find the page again and update your URL.

This move was somewhat spurred by the coverage I’ll be doing from CES this year which will include blog postings as well as some A/V material which will be available through a separate site that will be launching soon. Another reason for the move is that the site has finally received a makeover that has been more than three years in the works and was started over from scratch several times (what can I say, I’m busy). That site now contains some introductory material about myself as well as some information on the many other projects and things I have going on.