Docker Community Forums

Share and learn in the Docker community.

Issues with sudo systemctl status docker

Hello all,

I am running into some issues when running sudo systemctl status docker. I am getting the following errors:

level=warning msg="Your kernel does not support cgroup rt runtime"
level=warning msg="Your kernel does not support cgroup blkio weight"
level=warning msg="Your kernel does not support cgroup blkio weight_device"

Any help would be greatful, I am running docker in Ubuntu 18.04.5 LTS. Thanks in advance!

It seems that in newer versions of docker and Ubuntu the unit file for docker is simply masked (pointing to /dev/null).
You can verify it by running the following commands in the terminal:

sudo file /lib/systemd/system/docker.service
sudo file /lib/systemd/system/docker.socket
You should see that the unit file symlinks to /dev/null.
In this case, all you have to do is follow S34N’s suggestion, and run:

sudo systemctl unmask docker.service
sudo systemctl unmask docker.socket
sudo systemctl start docker.service
sudo systemctl status docker
I’ll also keep the original post, that answers the error log stating that the storage driver should be replaced:

Original Post

I had the same problem, and I tried fixing it with Salva Cort’s suggestion, but printing /etc/default/docker says:

THIS FILE DOES NOT APPLY TO SYSTEMD

So here’s a permanent fix that works for systemd (Ubuntu 15.04 and higher):

create a new file /etc/systemd/system/docker.service.d/overlay.conf with the following content:

[Service]
ExecStart=
ExecStart=/usr/bin/docker daemon -H fd:// -s overlay
flush changes by executing:

sudo systemctl daemon-reload
verify that the configuration has been loaded:

systemctl show --property=ExecStart docker
restart docker:

sudo systemctl restart docker

Belated answer, but looks like the Ubuntu kernel does not support the rt cgroup (for real time scheduling), and while it does support the blkio cgroup, it appears the weight and weight_device are missing.

I have Ubuntu Eoan and see something similar:

Sep 24 16:06:55 eoan dockerd[22285]: time="2020-09-24T16:06:55.765303211-07:00" level=warning msg="Your kernel does not support swap memory limit"
Sep 24 16:06:55 eoan dockerd[22285]: time="2020-09-24T16:06:55.765999749-07:00" level=warning msg="Your kernel does not support cgroup rt period"
Sep 24 16:06:55 eoan dockerd[22285]: time="2020-09-24T16:06:55.766432459-07:00" level=warning msg="Your kernel does not support cgroup rt runtime"
Sep 24 16:06:55 eoan dockerd[22285]: time="2020-09-24T16:06:55.767098539-07:00" level=warning msg="Your kernel does not support cgroup blkio weight"
Sep 24 16:06:55 eoan dockerd[22285]: time="2020-09-24T16:06:55.767616192-07:00" level=warning msg="Your kernel does not support cgroup blkio weight_device"

And looking into the blkio cgroup I don’t see the weight* files (not sure if these were removed recently):

/sys/fs/cgroup/blkio/docker$ l
total 0
--w------- 1 root root 0 Oct  9 15:21 blkio.reset_stats
-r--r--r-- 1 root root 0 Oct  9 15:21 blkio.throttle.io_service_bytes
-r--r--r-- 1 root root 0 Oct  9 15:21 blkio.throttle.io_service_bytes_recursive
-r--r--r-- 1 root root 0 Oct  9 15:21 blkio.throttle.io_serviced
-r--r--r-- 1 root root 0 Oct  9 15:21 blkio.throttle.io_serviced_recursive
-rw-r--r-- 1 root root 0 Oct  9 15:21 blkio.throttle.read_bps_device
-rw-r--r-- 1 root root 0 Oct  9 15:21 blkio.throttle.read_iops_device
-rw-r--r-- 1 root root 0 Oct  9 15:21 blkio.throttle.write_bps_device
-rw-r--r-- 1 root root 0 Oct  9 15:21 blkio.throttle.write_iops_device
drwxr-xr-x 2 root root 0 Oct  9 15:21 buildkit
-rw-r--r-- 1 root root 0 Oct  9 15:21 cgroup.clone_children
-rw-r--r-- 1 root root 0 Oct  9 15:21 cgroup.procs
-rw-r--r-- 1 root root 0 Oct  9 15:21 notify_on_release
-rw-r--r-- 1 root root 0 Oct  9 15:21 tasks