I have a docker problem which - when consulting the web - seems to happen quite often. Still, I didn't find among the million post I read and tried a solution. I can start "systemctl start docker.socket", but not "systemctl start docker", neither "sudo dockerd" seems to work, at least "ps aux | grep docker" does not give any hits. Maybe there is some specific error I am missing?

System

I run a Raspbian GNU/Linux 9 (Linux version 4.19.66-v7+ (dom@buildbot) (gcc version 4.9.3 (crosstool-NG crosstool-ng-1.22.0-88-g8460611)) #1253 SMP Thu Aug 15 11:49:46 BST 2019) on a ARMv7 Processor rev 4 (v7l) hardware.

Config

The docker-relevant configuration files look as follows:

/lib/systemd/system/docker.service

[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
BindsTo=containerd.service
After=network-online.target firewalld.service containerd.service
Wants=network-online.target
Requires=docker.socket

[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker
ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock
ExecReload=/bin/kill -s HUP $MAINPID
TimeoutSec=0
RestartSec=2
Restart=always

# Note that StartLimit* options were moved from "Service" to "Unit" in systemd 229.
# Both the old, and new location are accepted by systemd 229 and up, so using the old location
# to make them work for either version of systemd.
StartLimitBurst=3

# Note that StartLimitInterval was renamed to StartLimitIntervalSec in systemd 230.
# Both the old, and new name are accepted by systemd 230 and up, so using the old name to make
# this option work for either version of systemd.
StartLimitInterval=60s

# Having non-zero Limit*s causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity

# Comment TasksMax if your systemd version does not support it.
# Only systemd 226 and above support this option.
TasksMax=infinity

# set delegate yes so that systemd does not reset the cgroups of docker containers
Delegate=yes

# kill only the docker process, not all processes in the cgroup
KillMode=process

[Install]
WantedBy=multi-user.target

/lib/stytemd/system/docker.socket

[Unit]
Description=Docker Socket for the API
PartOf=docker.service

[Socket]
ListenStream=/var/run/docker.sock
SocketMode=0660
SocketUser=root
SocketGroup=docker

[Install]
WantedBy=sockets.target

Output of "sudo systemctl status docker":

* docker.service - Docker Application Container Engine
   Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Mon 2020-11-09 09:20:38 CET; 1s ago
     Docs: https://docs.docker.com
  Process: 7915 ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock (code=exited, status=2)
 Main PID: 7915 (code=exited, status=2)
      CPU: 2.179s

Nov 09 09:20:37 cryring-ecool dockerd[7915]: lr      0xffffffff
Nov 09 09:20:37 cryring-ecool dockerd[7915]: pc      0x76c6c45c
Nov 09 09:20:37 cryring-ecool dockerd[7915]: cpsr    0x10
Nov 09 09:20:37 cryring-ecool dockerd[7915]: fault   0x0
Nov 09 09:20:38 cryring-ecool systemd[1]: docker.service: Service hold-off time over, scheduling restart.
Nov 09 09:20:38 cryring-ecool systemd[1]: Stopped Docker Application Container Engine.
Nov 09 09:20:38 cryring-ecool systemd[1]: docker.service: Start request repeated too quickly.
Nov 09 09:20:38 cryring-ecool systemd[1]: Failed to start Docker Application Container Engine.
Nov 09 09:20:38 cryring-ecool systemd[1]: docker.service: Unit entered failed state.
Nov 09 09:20:38 cryring-ecool systemd[1]: docker.service: Failed with result 'exit-code'.

Output of "journalctl -b -u docker"

Past of journalctl output in Pastebin. It shows several lines with "SIGABRT: abort" which I cannot fully understand. Due to limitations of my account I had to delete parts of the log and concentrated on the "abort" parts.