Can't run docker hello-world: mountpoint for devices not found

Question

New to docker.

Installed docker from software management tool in mint 17.

When I run docker run hello-world I receive:

FATA[0000] Error response from daemon: Cannot start container a6bcc1ede2c38cb6b020cf5ab35ebd51b64535af57fa44f5966c37bdf89c8781: [8] System error: mountpoint for devices not found 

When I look at the service logs (/var/log/upstart/docker.log) I see:

ERRO[0617] Couldn't run auplink before unmount: exec: "auplink": executable file not found in $PATH 
ERRO[0617] Couldn't run auplink before unmount: exec: "auplink": executable file not found in $PATH 

: docker version

Client version: 1.6.2
Client API version: 1.18
Go version (client): go1.2.1
Git commit (client): 7c8fca2
OS/Arch (client): linux/amd64
Server version: 1.6.2
Server API version: 1.18
Go version (server): go1.2.1
Git commit (server): 7c8fca2
OS/Arch (server): linux/amd64

: docker info

Containers: 2
Images: 1
Storage Driver: aufs
 Root Dir: /var/lib/docker/aufs
 Backing Filesystem: extfs
 Dirs: 5
 Dirperm1 Supported: false
Execution Driver: native-0.2
Kernel Version: 3.13.0-24-generic
Operating System: Ubuntu 14.04.3 LTS
CPUs: 8
Total Memory: 15.6 GiB
Name: DWDEV-HOME-HBABAI
ID: K4GX:DTV6:547V:U3BO:YEOA:WVNU:NZEZ:L3GG:4W7U:IXNS:X3QK:5PVR
WARNING: No memory limit support
WARNING: No swap limit support

---

Update:

Installed sudo apt-get install aufs-tools, restarted docker service. I no longer see the following error:

ERRO[0617] Couldn't run auplink before unmount: exec: "auplink": executable file not found in $PATH 

However, in the logs I see that when docker is starting it is warning me about memory mount point:

INFO[0000] -job init_networkdriver() = OK (0)           
/var/run/docker.sock is up
WARN[0000] mountpoint for memory not found              
INFO[0000] Loading containers: start.         

I have a feeling it has to do with cgroup...but i don't know anything about that technology (yet)...

Answer 1

It turned out that I needed to install cgroup-lite. It was a shot in the dark but I followed this answer

Answer 2

I will add another answer here for app-people seeing this in 2020 on Debian, as my resolution to this problem was not present in any of the search hits found when googling the error string "mountpoint for devices not found".

Background:

• Debian 8.11 running on Google Cloud Platform
• Had a working Docker install 5 weeks ago with two containers running

Suddenly realised something had made the containers crash. The only remotely probable cause I could come up with was that I had deleted a parent folder on the host of which a subfolder was mapped as a volume. Another reason could be the mounting of an additional physical device.

The end result in any case was that trying to start any docker container resulted in the error message seen in the question ("mountpoint for devices not found") and no reboot (and hence upgrade of the kernel) had taken place.

The steps I took to debug the issue was

1. Inspect the logs: journalctl -xn | less. Didn't really contain too much additional info
2. Stop the Docker daemon (/etc/init.d/docker stop).
3. Add a file /etc/docker/daemon.json where the sole content was {"debug": true}
4. Try restarting the docker daemon only to see it fail
5. Inspect the logs, which would now be filled with a lot more info

These cgroup related errors were the ones that led to the answer:

Jan 13 20:17:15 dev-acme-org dockerd[9022]: time="2020-01-13T20:17:15.964631675Z" level=warning msg="Your kernel does not support cgroup memory limit"
Jan 13 20:17:15 dev-acme-org dockerd[9022]: time="2020-01-13T20:17:15.964654637Z" level=warning msg="Unable to find cpu cgroup in mounts"
Jan 13 20:17:15 dev-acme-org dockerd[9022]: time="2020-01-13T20:17:15.964667575Z" level=warning msg="Unable to find blkio cgroup in mounts"
Jan 13 20:17:15 dev-acme-org dockerd[9022]: time="2020-01-13T20:17:15.964680057Z" level=warning msg="Unable to find cpuset cgroup in mounts"
Jan 13 20:17:15 dev-acme-org dockerd[9022]: time="2020-01-13T20:17:15.964750643Z" level=warning msg="mountpoint for pids not found"
Jan 13 20:17:15 dev-acme-org dockerd[9022]: time="2020-01-13T20:17:15.980250151Z" level=debug msg="Cleaning up old mountid : start."
Jan 13 20:17:15 dev-acme-org dockerd[9022]: Error starting daemon: Devices cgroup isn't mounted

OK, something about cgroups and mounting. That led me to a workaround for a different cgroups issue that could be applied in this case, of which the the only commands that seemed to have an effect were

1. /etc/init.d/docker stop
2. cgroupfs-mount
3. /etc/init.d/docker start

Now, upon starting Docker again, the logs still contained a few lines of cgroup related errors:

Jan 13 20:24:42 dev-acme-org dockerd[9775]: time="2020-01-13T20:24:42.258571633Z" level=warning msg="Your kernel does not support cgroup memory limit"
Jan 13 20:24:42 dev-acme-org dockerd[9775]: time="2020-01-13T20:24:42.258591020Z" level=warning msg="Unable to find cpu cgroup in mounts"
Jan 13 20:24:42 dev-acme-org dockerd[9775]: time="2020-01-13T20:24:42.258937091Z" level=warning msg="mountpoint for pids not found"

But half of them (blkio, cpuset) were gone, and more importantly, the next line read:

Jan 13 20:24:42 dev-acme-org dockerd[9775]: time="2020-01-13T20:24:42.259420798Z" level=info msg="Loading containers: start."

And finally

Unit docker.socket has finished starting up.

So, basically, remounting the cgroup stuff fixed the issue. No need to reboot.