I've been evaluating a ZFS-on-NBD based backup system for several weeks. I've now made a decision if I want to adopt this new setup, or stick with S3QL. To make it short, I will drop my experiments with ZFS and continue using S3QL. The main reasons for this are that the advantages of using ZFS are not as big as I had hoped, and that I discovered additional problems with the setup. But let me start…
When I created S3QL in 2008, the Cloud Storage and Linux filesystem landscape looked rather different than today: there was no filesystem that supported compression, encryption, or de-duplication of data. The only relevant cloud storage system was Amazon S3, and it only offered eventual consistency. S3QL was designed to fill these gaps: I wanted to be able to store compressed, encrypted, and…
I consider it fairly uncontroversial that, as a programming language, MATLAB is a terrible choice. However, I found out that to some people this isn't actually obvious at all - especially when their first exposure to programming was through MATLAB. Explaining why the MATLAB language is so bad isn't easy to do in a quick hallway conversation, so I wrote this blog post as a resource I can refer…
I recently found myself in the situation of wanting to get out of a lease before its contractual maturity date. The most cost-effective way to do so is to transfer the lease to someone else. swapalease.com is one of the companies that promises to bring together people for such transactions. I will say straightaway that I was very skeptical. Swapalease charges not just a provision when the lease is…
A little while ago I blogged about SSD caching under Linux and promised to report back should I encounter any problems with the (rather complex) stack of btrfs on dm-crypt on lvm on bcache. I have now run this setup for several months and indeed encountered a few issues. The first issue is that attempting to read from a freshly created file sometimes results in I/O errors that persist until the…
Git has arguable become the most widely used version control system in the open-source and free software communities. However, if you can live without GitHub and don't need to manage a code base as large as e.g. the Linux kernel, you are much better of using Mercurial . Here is why.
I recently set up a fresh Windows 7 system. While the installation completed without hassles, I was worried that an attempt to run Windows Update seemed to freeze in the "Checking for Updates" state. The problem with Windows problems In my opinion, there are two major issues that make fixing any problems with a Windows system a major headache. The first one is the completely absence of error…
Gnus is a mail user agent (MUA) and newsreader written in Emacs Lisp . It is famous for being very configurable, and for being one of the few MUAs that come with a decent editor to compose your messages (by virtue of actually running inside Emacs ). I have switched between Gnus and Thunderbird as my primary MUA several times over the years and recently switched to Gnus again. This time, however, I…
I recently found myself with a spare 128 GB SSD disk and decided to try my hand at setting up SSD caching under Linux. My personal desktop system so far stored all data on traditional spinning disks. However, a little while ago I got a new computer at work that comes exclusively with SSD storage, and since then I've become increasingly annoyed with the disk performance of my personal system. Using…
As a long-time Mercurial user, I recently learned to use Git. This article describes the differences that I found most interesting. It is primarily targeted at people who know only one of the systems and are interested in the other.
Overall, the X1 is well designed. The picture quality is very good and the support is very response. The installation is relatively straightforward. However, in my opinion the camera fails where it matters most: in reliably saving footage of critical situations.
I believe Python's ExitStack feature does not get the recognition it deserves. I think part of the reason for this is that its documentation is somewhere deep down in the (already obscure) contextlib module because formally ExitStack is just one of many available context managers for Python's with statement . But ExitStack deserves far more prominent notice than that. This post will hopefully help…
I recently stumbled over a nasty bug when playing The Witcher 2 with FCR (the Full Combat Rebalance mod). The symptoms are that all of a sudden your vigor is stuck at zero and does not re-generate anymore. If you look at your character attributes, you will find that vigor regeneration has indeed changed to zero both in and outside of combat. There are other reports of this problem to be found in…
This is a review for Zoo , book one of the Enclosure Chronices written by Tara Elizabeth. Zoo is written in the first person. The protagonist, Emma, tells the story of how she dies and then wakes up in an "Anthropologic Center" in the future. We quickly learn that at some point in the future, time travel was invented but quickly banned because it caused all sorts of problems. However, there is one…
This is a review for the first book of the Exodus series written by Doug Dandridge. Empires at War comes across as an ambitious project. There is a huge number of characters, locations, and plot lines. Normally this is something that I like (for example, I think the Nights Dawn triology from Peter Hamilton is fantastic), but in this case I have the feeling that too much has been compressed into a…
I occasionally want to know at which version a specific change was first released. Finding the commit that introduced the change is typically easy using hg blame . However, it always takes me several minutes to figure out the correct syntax to figure out the command to find the oldest tagged descendant of this changeset, i.e. (assuming you are tagging releases) the first release that contains the…
This is a review for The long way to a small, angry planet , written by Becky Chambers. This is a very interesting book. The overarching plot is not particularly novel or intriguing, but the author does an amazing job describing the different characters and the world they live in. Normally, the lack of an intriguing story arc is something that I very much dislike (e.g. I think that Kim Robinsons'…
This is a review for the second book in the Russell's Attic series by SL Huang. I really liked the first book in this series (Zero-sum game), but unfortunately the second one does not reach the quality of the first. At the beginning, the story is very slow-paced and tedious, but it picks up in the second half. However, at that point the overall story arc also becomes rather predictable (in short,…
This is a review for Mastering C-Make , written by Ken Martin, and published by Kitware. I bought this book in the hope of getting a structured introduction to CMake. While the CMake online documentation appears to be comprehensive, it seems mostly intended as a reference and is thus rather difficult to use as a starting point, so I was hoping this book would provide more guidance. Unfortunately…
This is a review for the second book in the The Lost Fleet: Beyond the Frontier series by Jack Campbell. Here is a best-of of the first ~20% of the book. I don't think there are any significant spoilers. The main protagonist has the rank of admiral, his wife is captain on his flagship. They have to be careful not to stand too close to each other when looking at a screen (it would be inappropriate)…
This is a review for the Mistborn series from Brandon Sanderson, covering both Mistborn , The Well of Ascension , and The Hero of Ages . I'm the kind of person who gets annoyed quickly by even small inconsistencies in plot, world setup, and character behavior. Yet I found this book thoroughly enjoyable. There is a fantastic big story ark spanning over all three books, yet every single book also…
Rackspace is rightfully praised for its use and development of open source technologies like OpenStack. However, I have had some rather shocking experiences when contacting their technical support. What I have seen was in fact sufficently bad for me to feel the need to document it here as a warning for others. The bottom line is, all support agents I was in contact with had minimal expertise…
This is a review for the second book in the Koban series by Stephen W. Bennett. Apart from a few incongruities I liked the first book of this series ("Koban") a lot and was looking forward to the sequel. Unfortunately "The Mark of Koban" fell short of my expectations. Instead of improving upon the few things that didn't feel quite right in the first book, the sequel feels a lot less…
This is a review for the first book in the Koban series by Stephen Bennett. This review may sound rather critical, so let me begin by stating that overall, I enjoyed the book a lot. However, there were three issues that really disappointed/annoyed me disproportionally. So when continuing to read, keep in mind that these are really the only negative points that I noticed, i.e. in every other aspect…
This is a review for the first book in the Rho Agenda series by Richard Phillips. I've stopped reading this after the first ~20% of the book, so the following may contain spoilers from up to then. That said, in my opinion most the story is so predictable that reading this is really not going to ruin anything for you. So, what happens? Well, the book starts with a just-graduated postdoc setting up…
This is a review for the second book in the Chaos Chronicles by Jeffrey A. Carver. It is preceded by Neptune Crossing . I enjoyed Neptune Crossing very much and couldn't wait to read this book. However, I have to say that it was quite a disappointment. The characters all remain very flat and unconvincing. The whole book consists of Bandicut and a couple of fellow aliens chasing and being chased by…