Disk caching in the year 2020

In the previous blog post I went over the design of storage systems and how they protect themselves from data loss in the face of disk failure or unclean shutdowns. If you’re putting together the hardware yourself modern Linux systems and modern hardware give you endless cost, performance and durability tradeoffs for whatever system you want. But 2020 also gives us the cloud, and storage systems in the cloud whose durability far exceeds whatever you could build yourself.

Durability in the year 2020

It is the year 2020 and we still don’t have great answers to data durability in the face of unclean shutdowns. Unclean shutdowns are things like power outages, system faults and unlucky kernel panics and preventing data loss when they happen is a hard problem. I’m going to talk through a few ways these can cause data loss in this blog post but you can probably come up with new ones on your own - exotic failures that no system will ever handle correctly. In the year 2020, the conventional wisdom is still true. Always take backups, and RAID is no substitute for backups.


I had the desire to go to Japan, and especially Tokyo, because I wanted to spend my next trip in an urban area doing urban things. I felt that the last few vacations had a focus on exploring nature and natural wonders and I wanted to try going the other way. Tokyo is a massive urbanized area with the largest urban population in the world and endless things to do so it fit my goals well.

9/2, the afternoon:

My criticism of dotdrop, a dotfile management system

Git, the command-line version control system, was initially released on April 7, 2005. Github launched to the public on April 10, 2008 and was the killer application that promoted Git beyond its initial audience of systems programmers. By 2010 it was clear to me that the industry was moving away from Subversion and Git was the new standard in version control. I took it upon myself to git with the times and learn it for myself.