Linux

One of the things I find quite annoying is cleaning up Docker images on a development machine, such as my laptop. Over time, they tend to accumulate as you experiment with things, clogging up your machine. It’s really handy to have a quick and easy way to get rid of them. As I typically work from the command line, I wanted a way to do it there, and so I created a shell alias that does it in combination with fzf.

Recently, I upgraded my Ubuntu 12.04 server, which uses an encrypted root directory (with LVM and LUKS). Unfortunately, somewhere along the way the upgrade broke the boot process - next time I booted, it hung for 5 seconds, then timed out and dropped to a BusyBox prompt. I quickly found a workaround which allowed me to manually intervene and continue the boot each time:

cryptsetup luksOpen /dev/sda5 root
exit

Of course, however, I didn’t want to intervene on every boot, especially since this is normally a headless server. To fix it longterm, I eventually found this link, which hinted at the problem. Essentially, I had to locate the mapper name for the partition containing my LVM physical volume which contained the boot logical volume. I found this in /etc/crypttab, and in my case it was flash_crypt:

Update 2011-08-26: If you are using Ubuntu 11.04 or later, it looks like this is now packaged as a .deb by PlayDeb. This post may still be of interest to those using earlier versions of Ubuntu.

I recently had cause to install FlightGear 2.4.0 on Ubuntu 10.04. It’s not packaged in the form of a deb yet, so I’ve documented the commands I used. No guarantees this’ll work for you, as I haven’t tested them rigorously; and I’m assuming some Linux and command-line knowledge.

The son of one of the world’s most influential and talented economists is obviously a total geek. How wonderful.

Oh, and get this blog comment and response.

Update 16:58: Then, of course, you read this.

Why don’t economists get any respect?