Docker failed to restart with data on mount hard drive - docker

Question

I mount a hard drive on /mnt/data with mount /dev/vdb /mnt/data
Change default docker folder inside : /etc/docker/daemon.json by
{
"graph": "/mnt/data/docker"
}
Everything work fine.
but after a computer restart :
docker daemon can't restart
I got these error :
$ service docker start
Job for docker.service failed because the control process exited with error code. See "systemctl status docker.service" and "journalctl -xe" for details.
and
$ systemctl status docker.service
● docker.service - Docker Application Container Engine
Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
Active: inactive (dead) (Result: exit-code) since Thu 2017-10-05 13:58:58 UTC; 45s ago
Docs: https://docs.docker.com
Process: 5896 ExecStart=/usr/bin/dockerd -H fd:// (code=exited, status=1/FAILURE)
Main PID: 5896 (code=exited, status=1/FAILURE)
Oct 05 13:58:58 mycomputer systemd[1]: Failed to start Docker Application Container Engine.
Oct 05 13:58:58 mycomputer systemd[1]: docker.service: Unit entered failed state.
Oct 05 13:58:58 mycomputer systemd[1]: docker.service: Failed with result 'exit-code'.
Oct 05 13:58:58 mycomputer systemd[1]: docker.service: Service hold-off time over, scheduling restart.
Oct 05 13:58:58 mycomputer systemd[1]: Stopped Docker Application Container Engine.
Oct 05 13:58:58 mycomputer systemd[1]: docker.service: Start request repeated too quickly.
Oct 05 13:58:58 mycomputer systemd[1]: Failed to start Docker Application Container Engine.

Answer 1

Docker is starting before your non-OS disk (mnt/data/docker) is mounted. You can ask docker to wait for a successful mount before starting docker.
Find the mount, edit your Docker systemd service file to require and wait for the mount before starting.
systemctl list-units --type==mount # Lists all the mounts.
systemctl status <example.mount> # Get details about mount. Find the one which matches your mount directory
sudo nano /lib/systemd/system/docker.service # Edit your systemd service file
Add the <example.mount> name at the end of the "After" and "Requires" row.
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
BindsTo=containerd.service
After=network-online.target firewalld.service containerd.service <example.mount>
Wants=network-online.target
Requires=docker.socket <example.mount>
...
sudo systemctl daemon-reload
sudo systemctl restart docker.service