@@ -170,34 +170,42 @@ If you want Docker to start at boot, you should also:

 ### Configuring Docker

-You configure the `docker` daemon in the `/etc/sysconfig/docker` file on your

-host. You do this by specifying values in a variable. For CentOS 7.x and RHEL 7.x, the name

-of the variable is `OPTIONS` and for CentOS 6.x and RHEL 6.x, the name of the variable is

-`other_args`. For this section, we will use CentOS 7.x as an example to configure the `docker`

-daemon.

+For CentOS 7.x and RHEL 7.x you can [control and configure Docker with systemd](systemd.md).

-By default, systemd services are located either in `/etc/systemd/service`, `/lib/systemd/system`

-or `/usr/lib/systemd/system`. The `docker.service` file can be found in either of these three

-directories depending on your host.

+Previously, for CentOS 6.x and RHEL 6.x you would configure the `docker` daemon in 

+the `/etc/sysconfig/docker` file on your system. You would do this by specifying 

+values in a `other_args` variable. For a short time in CentOS 7.x and RHEL 7.x you 

+would specify values in a `OPTIONS` variable. This is no longer recommended in favor 

+of using systemd directly. 

+

+For this section, we will use CentOS 7.x as an example to configure the `docker` daemon. 

 To configure Docker options:

 1. Log into your host as a user with `sudo` or `root` privileges.

-2. If you don't have one, create the `/etc/sysconfig/docker` file on your host. Depending on how

-you installed Docker, you may already have this file.

+2. Create the `/etc/systemd/system/docker.service.d` directory.

-3. Open the file with your favorite editor.

+    ```

+    $ sudo mkdir /etc/systemd/system/docker.service.d

+    ```

+

+3. Create a  `/etc/systemd/system/docker.service.d/docker.conf` file.

+

+4. Open the file with your favorite editor.

     ```

-    $ sudo vi /etc/sysconfig/docker

+    $ sudo vi /etc/systemd/system/docker.service.d/docker.conf

     ```

-4. Add a `OPTIONS` variable with the following options. These options are appended to the

-command that starts the `docker` daemon.

+5. Override the `ExecStart` configuration from your `docker.service` file to customize 

+the `docker` daemon. To modify the `ExecStart` configuration you have to specify 

+an empty configuration followed by a new one as follows:

 ```

-    OPTIONS="-D --tls=true --tlscert=/var/docker/server.pem --tlskey=/var/docker/serverkey.pem -H tcp://192.168.59.3:2376"

+[Service]

+ExecStart=

+ExecStart=/usr/bin/docker daemon -H fd:// -D --tls=true --tlscert=/var/docker/server.pem --tlskey=/var/docker/serverkey.pem -H tcp://192.168.59.3:2376

 ```

 These options :

@@ -209,15 +217,21 @@ These options :

 The command line reference has the [complete list of daemon flags](../reference/commandline/daemon.md)

 with explanations.

-5. Save and close the file.

+6. Save and close the file.

-6. Restart the `docker` daemon.

+7. Flush changes.

+

+    ```

+    $ sudo systemctl daemon-reload

+    ```

+

+8. Restart the `docker` daemon.

     ```

     $ sudo systemctl restart docker

     ```

-7. Verify that the `docker` daemon is running as specified with the `ps` command.

+9. Verify that the `docker` daemon is running as specified with the `ps` command.

     ```

     $ ps aux | grep docker | grep -v grep