cannot start docker daemon (graphdriver issue) - docker

Question

running Ubuntu 16.04.5 LTS 4.4.0-108-generic on a virtual private server
My aim is to deploy a meteor application with mup.js,
but it fails because of dockerd not being launched. The problem is, i cannot get dockerd to launch after a system reboot.
I tried changing graphdriver as suggested in other threads
(Not able to start docker on Ubuntu 16.04.2 LTS (error initializing graphdriver)), switching to aufs or overlay2, but to no avail. I also updated my kernel, purged docker repos, reinstalled docker on my machine.
i have close to no experience working with docker, and the website i'm trying to put back online is part of a show, the last night of which is tomorrow! i must say i'm getting a bit desperate, any help is welcome.
thank you!
docker & dockerd are both version 18.06.1-ce, build e68fc7a
$ sudo dockerd
INFO[0000] libcontainerd: new containerd process, pid: 3488
WARN[0000] containerd: low RLIMIT_NOFILE changing to max current=1024 max=1048576
WARN[0000] failed to rename /var/lib/docker/tmp for background deletion: %!s(<nil>). Deleting synchronously
Error starting daemon: error initializing graphdriver: driver not supported
journalctl -xe yields :
Oct 03 01:22:19 vps332343 systemd[1]: Listening on Docker Socket for the API.
-- Subject: Unit docker.socket has finished start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit docker.socket has finished starting up.
--
-- The start-up result is done.
Oct 03 01:22:19 vps332343 systemd[1]: docker.service: Start request repeated too quickly.
Oct 03 01:22:19 vps332343 systemd[1]: Failed to start Docker Application Container Engine.
-- Subject: Unit docker.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit docker.service has failed.
--
-- The result is failed.
Oct 03 01:22:19 vps332343 systemd[1]: docker.socket: Unit entered failed state.
Oct 03 01:22:37 vps332343 sudo[3651]: eboutin : TTY=pts/0 ; PWD=/etc/nginx/sites-available ; USER=root ; COMMAND=/bin/journalctl -xe
Oct 03 01:22:37 vps332343 sudo[3651]: pam_unix(sudo:session): session opened for user root by eboutin(uid=0)
df -tH yields :
Filesystem Type Size Used Avail Use% Mounted on
udev devtmpfs 970M 0 970M 0% /dev
tmpfs tmpfs 196M 5.6M 190M 3% /run
/dev/vda1 ext4 9.7G 4.6G 5.1G 48% /
copymods tmpfs 977M 28K 977M 1% /lib/modules
tmpfs tmpfs 977M 68K 977M 1% /dev/shm
tmpfs tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs tmpfs 977M 0 977M 0% /sys/fs/cgroup
tmpfs tmpfs 196M 0 196M 0% /run/user/1002
tmpfs tmpfs 196M 0 196M 0% /run/user/1001
/etc/docker/daemon.json contents :
{"storage-driver":"devicemapper"}
(no other modified config file)

Answer 1

Try to configure devicemapper as a storage driver and clean /var/lib/docker/ folder before docker start rm -rf /var/lib/docker/* (it will delete all your previous containers/volumes/...).
Check any warnings from docker info, when docker will be running - they may help you with additional configuration.

Answer 2

This can also be due to a recent kernel update that might have messed up the graphdriver: devicemapper.
So when rm -rf /var/lib/docker/* and reinstalling Docker does not work. Try reinstalling kernel image and reboot.
$ sudo apt-get install --reinstall linux-image-`uname -r`
$ sudo reboot