I'm working through the docker installation guide. Running CentOS 7. I ran:

curl -sSL https://get.docker.com/ | sh


warning: /var/cache/yum/x86_64/7/docker-main-repo/packages/docker-engine-1.8.2-1.el7.centos.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID XXXXXX: NOKEY Public key for docker-engine-1.8.2-1.el7.centos.x86_64.rpm is not installed. Importing GPG key

There's a little more after that about Userid, Fingerprint, from.

Next I ran:

sudo service docker start


Starting docker (via systemctl): Job for docker.service failed. See 'systemctl status docker.service' and 'journalctl -xn' for details. [FAILED]

I don't know what this message is referring to. How can I fix this?

systemctl status docker.service result:

docker.service timed out. Terminating. Failed to start docker application container engine Unit docker.service entered failed state

  • What does systemctl status docker.service show?
    – jordanm
    Commented Sep 12, 2015 at 0:25
  • Updated question with info @jordanm Commented Sep 12, 2015 at 1:38
  • 3
    You might get better milage out of the docker packages that are distributed with CentOS, rather than ones provided by upstream. Docker is included in CentOS's 'extras' repository, and is actually built to work with CentOS.
    – jsbillings
    Commented Sep 12, 2015 at 12:52
  • @jsbillings I'd love to try that. I looked in /etc/yum.repos.d/ directory and there is no file called CentOS Extras. Do you know how to add this repo? According to centos wiki it should have been installed an enabled by default: wiki.centos.org/AdditionalResources/Repositories Commented Sep 12, 2015 at 19:32
  • 1
    @P.Brian.Mackey, I've checked this on a default installed CentOS 7 system and there the extras repository is indeed enabled by default - and yum search docker finds the docker packages. yum info docker prints 'Version : 1.8.2' and 'Repo : extras/7/x86_64'. Commented Mar 18, 2016 at 10:06

1 Answer 1


Check if you get more details in:

journalctl -u docker -xe

Similiar driver issues - by default it is devicemapper and can be configured for something else:



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