I upgraded an old server from Ubuntu 14.04 LTS to 16.04 LTS today and, when it restarted, I started getting “Read-only file system” errors on the root partition. Ouch! Here’s how I investigated and fixed the issue, including a list of the sites I found that helped me along the way. Am I out of disk space? I wasn’t sure if perhaps the installation had failed and corrupted something because I was out of disk space.
