Ubuntu 14.04 Dockerd : unknown option dirperm1 on startup

Trying to start the Dockerd service on an Ubuntu 14.04 server I ran into ‘sudo service docker start’ hanging, and in the logs seeing this message:

Mar  4 17:12:07 vps kernel: [58270.204343] aufs au_opts_parse:1155:dockerd[12023]: unknown option dirperm1

Mar  4 17:12:49 vps kernel: [58311.799010] init: docker post-start process (12015) terminated with status 1

This is described in this post here and here.

In the Docker CE for Ubuntu instructions, there’a a note for installing additional aufs support for 14.04 here:

sudo apt-get install \
    linux-image-extra-$(uname -r) \
    linux-image-extra-virtual

Note the Docker CE for Ubuntu install docs say for 16.04:

For Ubuntu 16.04 and higher, the Linux kernel includes support for OverlayFS, and Docker CE uses the overlay2 storage driver by default.

In this particular case I had mistakenly setup this VM from a 14.04 template, and I really wanted to be running 16.04. With 16.04 and the latest Docker install per the installed steps here, I didn’t run into this issue.