truenas# sudo systemctl start docker
Job for docker.service failed because the control process exited with error code.
See "systemctl status docker.service" and "journalctl -xe" for details.
#
truenas# journalctl -xe
░░ the configured Restart= setting for the unit.
Mar 05 13:51:47 truenas.local systemd[1]: Stopped Docker Application Container Engine.
░░ Subject: A stop job for unit docker.service has finished
░░ Defined-By: systemd
░░ Support: https://www.debian.org/support
░░
░░ A stop job for unit docker.service has finished.
░░
░░ The job identifier is 2295 and the job result is done.
Mar 05 13:51:47 truenas.local systemd[1]: Starting Docker Application Container Engine...
░░ Subject: A start job for unit docker.service has begun execution
░░ Defined-By: systemd
░░ Support: https://www.debian.org/support
░░
░░ A start job for unit docker.service has begun execution.
░░
░░ The job identifier is 2295.
Mar 05 13:51:47 truenas.local dockerd[25179]: time="2021-03-05T13:51:47.980156155-08:00" level=info msg="Starting up"
Mar 05 13:51:47 truenas.local dockerd[25179]: time="2021-03-05T13:51:47.981338525-08:00" level=info msg="parsed scheme: \"unix\"" module=grpc
Mar 05 13:51:47 truenas.local dockerd[25179]: time="2021-03-05T13:51:47.981353646-08:00" level=info msg="scheme \"unix\" not registered, fallback to default scheme" module=grpc
Mar 05 13:51:47 truenas.local dockerd[25179]: time="2021-03-05T13:51:47.981370565-08:00" level=info msg="ccResolverWrapper: sending update to cc: {[{unix:///run/containerd/containerd.sock  <nil> 0 <nil>}] <nil> <nil>}" m>
Mar 05 13:51:47 truenas.local dockerd[25179]: time="2021-03-05T13:51:47.981380688-08:00" level=info msg="ClientConn switching balancer to \"pick_first\"" module=grpc
Mar 05 13:51:47 truenas.local dockerd[25179]: time="2021-03-05T13:51:47.981989440-08:00" level=info msg="parsed scheme: \"unix\"" module=grpc
Mar 05 13:51:47 truenas.local dockerd[25179]: time="2021-03-05T13:51:47.982005325-08:00" level=info msg="scheme \"unix\" not registered, fallback to default scheme" module=grpc
Mar 05 13:51:47 truenas.local dockerd[25179]: time="2021-03-05T13:51:47.982018257-08:00" level=info msg="ccResolverWrapper: sending update to cc: {[{unix:///run/containerd/containerd.sock  <nil> 0 <nil>}] <nil> <nil>}" m>
Mar 05 13:51:47 truenas.local dockerd[25179]: time="2021-03-05T13:51:47.982027751-08:00" level=info msg="ClientConn switching balancer to \"pick_first\"" module=grpc
Mar 05 13:51:47 truenas.local dockerd[25179]: failed to start daemon: error initializing graphdriver: Cannot find root filesystem Disk 1/ix-applications/docker: Output does not match what is expected on this platform
Mar 05 13:51:47 truenas.local systemd[1]: docker.service: Main process exited, code=exited, status=1/FAILURE
░░ Subject: Unit process exited
░░ Defined-By: systemd
░░ Support: https://www.debian.org/support
░░
░░ An ExecStart= process belonging to unit docker.service has exited.
░░
░░ The process' exit code is 'exited' and its exit status is 1.
Mar 05 13:51:47 truenas.local systemd[1]: docker.service: Failed with result 'exit-code'.
░░ Subject: Unit failed
░░ Defined-By: systemd
░░ Support: https://www.debian.org/support
░░
░░ The unit docker.service has entered the 'failed' state with result 'exit-code'.
Mar 05 13:51:47 truenas.local systemd[1]: Failed to start Docker Application Container Engine.
░░ Subject: A start job for unit docker.service has failed
░░ Defined-By: systemd
░░ Support: https://www.debian.org/support
░░
░░ A start job for unit docker.service has finished with a failure.
░░
░░ The job identifier is 2295 and the job result is failed.