So true!
All posts by chris
Seagate Exos disks in TrueNAS Core: Disable parking of heads
My NAS (TrueNAS Core) is running with Seagate Exos X16 drives. Those were considerably cheaper than any other drive at the time of purchase (September 2020) here in Germany. From what I gathered since then, this is often still the case, also in other countries.
But there is one aspect about these drives that needs attention. Being marketed for data center use, they have a very small timeout for parking their heads. So, if an Exos drive is idle for only a very short time, it will move its heads into a parking position. That is a reasonable setting for data centers, where drives are hardly ever idle. But for a small business or home use it is less than ideal.
Fortunately, this setting can be changed and TrueNAS Core, or rather the underlying FreeBSD, has the right program for this already installed. Below you find the command that I am using. You will need to adjust the device, but otherwise you can just run it.
camcontrol epc /dev/??? -c state -d -p Idle_b -s
In terms of the ATA level, this disables the Idle_b power condition and saves it to the drive to survive a reboot. For more details, please check out the extensive man page of the camcontrol command.
In addition I recommend that you configure your system to issue this command on every startup. Under normal conditions that is not necessary. But what if you need to replace a disk drive? If you have a case with hot-swappable drive bays, this will of course not help. In that case I would think about a cron job.
Dave Farley: My Response To The NONSENSE McKinsey Article On Developer Productivity
Dave smashes the article on developer productivity from McKinsey.
Randy Shoup: Large-Scale Architecture: The Unreasonable Effectiveness of Simplicity
Some interesting things to learn here. The video was a bit superficial for me, in that a lot of things just get thrown at you. Its value, for me, comes from that list of things, which each deserve looking at in more detail using separate sources.
Dave Farley: Why Software Release Cycles Are SO PAINFUL
Great video from Dave Farley
Jens Schauder: Domain-Driven Design with Relational Databases Using Spring Data JDBC
Interesting video about the real-world challenges when using an ORM (object-relational mapper) like Hibernate or JPA in general.
You should also check out the following articles mentioned in the talk:
- David L. Parnas: On the criteria to be used in decomposing systems into modules
- Vaughn Vernon: Effective Aggregate Design
Largely moved to LinkedIn
It has been a long time since I wrote something here. Apart from being busy the main reason is that I moved most of writing activity to LinkedIn, where I simply reach more people.
Please feel free to follow me there at https://www.linkedin.com/in/christophjahn/
Every now and then I will still post here, primarily more technical stuff. So you should still check from time to time.
Steve Jobs President & CEO, NeXT Computer Corp and Apple. MIT Sloan Distinguished Speaker Series
This is a truly remarkable video. I sometimes wish, and I am not a fanboy, that Steve Jobs would have moved into academia at some point and preserved much more of his experience and knowledge.
It is fascinating to hear Steve talk about strategy, corporate culture, marketing, and many other subjects. The video is from early 1992 and in my opinion many points are still bleeding edge today.
Chris Richardson: Not Just Events – Developing Asynchronous Microservices
For me the bottom line of this video is: Microservices come with a huge amount of challenges, that you do not have with a monolith. Chris covers a lot of topics, each of which deserve a number of dedicated videos.
Using Headphones for Learning
Just a quick note about one small way I have found to improve my learning when I watch YouTube videos. A while ago I realized that it was easier for me to follow complex content when wearing my old Sennheiser HD 600 headphones. They are not cheap, but relative to other models still quite affordable. And they are famous for their super-clear and neutral sound. Allegedly, this also makes them a preferred means for professional sound mixing. I had bought mine back in 2003 for listening to classical music.
Interestingly, though, the main use at the moment is for watching YouTube videos. There is a bunch of great content out about all aspects of software engineering, which is my topic of interest. When it comes to listening via headphones, my theory is that the super clear voices, relative to e.g. to the speakers of my laptop, free up a little bit of mental capacity. And this would then create the impression of grasping content more easily.