Leaking Free Disk Space

August 03, 2015

I’ve been watching a disk space leakage creep slowly upwards for months now; finally, I figured out where it was going!

Whenever I set up a VPS, I follow Brian Kennedy’s excellent My First 5 Minutes On A Server; Or, Essential Security for Linux Servers. It covers setting up a number of initial tools that make server administration much easier:

  • fail2ban, for blocking suspicious log in activity
  • setting up a non-root user
  • ufw, a simple firewall program
  • unattended-upgrades, which installs security upgrades periodically
  • logwatch, so you can read a digest of what’s happened in your logs

Ever since I set up my VPS, I’d seen the disk space creep up in the daily logwatch digest. I had looked a few times and figured it must be related to some sort of misconfiguration of the Ruby app server I have running on it right now.

Recently, it got up to more than half of my disk space gone. For a VPS that I used maybe twice a month, this was ridiculous. I investigated once more and finally came up with the culprit: unattended-upgrades wasn’t autoremoving packages. I had gigabytes worth of packages that could be autoremoved.

Solution

There’s a one-line config file fix. Add this to /etc/apt/apt.conf.d/50unattended-upgrades:

/etc/apt/apt.conf.d/50unattended-upgrades
...
// Do automatic removal of new unused dependencies after the upgrade
// (equivalent to apt-get autoremove)
Unattended-Upgrade::Remove-Unused-Dependencies "true";
...

Update: It looks like a bug in unattented-upgrades is preventing it from automatically removing header packages. For the time being you will have to either manually auto-remove these packages, or add sudo apt-get autoremove -y to your crontab.

Update: The bug has been addressed and closed. It now correctly removes header packages!

Lenses & Composition

It’s really cool how composition works with lenses! Continue reading

Some Intuition on Lenses

Published on February 06, 2018

Code Review from the Command Line

Published on January 13, 2018