Installing Docker

The StorageGRID Webscale system runs on RHEL or CentOS as a collection of Docker containers. Before you can install StorageGRID Webscale, you must install Docker.

Steps

  1. If you are installing Docker on Red Hat Enterprise Linux, activate the RHEL Extras channel.
    sudo subscription-manager repos --enable rhel-7-server-extras-rpms
    Note: The CentOS Extras repository is enabled by default.
  2. Install the Docker Engine.
    sudo yum install docker
  3. Reconfigure Docker in direct-lvm mode.

    On RHEL, CentOS, and Fedora, Docker uses the devicemapper storage driver. By default, after installation, it is configured in loopback-lvm mode. This mode is not suitable for production.

    1. After completing the Docker installation on a host, enter the command: sudo docker info
      If the output of this command shows that your Data loop file and Metadata loop file are files underneath /var/lib/docker/devicemapper/devicemapper, then Docker is configured in loopback-lvm mode.
    2. Reconfigure Docker in direct-lvm mode before continuing with this installation process.

      You will use the Docker storage pool volume you allocated for each host when configuring host storage as the block device backing your dm.thinpooldev container storage pool. The referenced instructions use the example block device name /dev/xvdf. You must replace /dev/xvdf with the persistent name of the Docker storage pool volume allocated to the host on which you are reconfiguring docker.

      Attention: If you use shared storage for the Docker storage pool volumes, you must use a different physical volume for each host. System data will be corrupted if two hosts attempt to use the same Docker storage pool volume for container storage.
  4. Ensure Docker has been enabled and started by running the following two commands:
    sudo systemctl enable docker
    sudo systemctl start docker
  5. Confirm you have installed the expected version of Docker by entering the following:
    sudo docker version
    The Client and Server versions must be 1.10.3 or later.
    Client:
      Version: 1.10.3
      API version: 1.22
      Package version: docker-common-1.10.3-46.el7.14.x86_64
      Go version: go1.6.2
      Git commit: 5206701-unsupported
      Built: Mon Aug 29 14:00:01 2016
      OS/Arch: linux/amd64
    
    Server:
      Version: 1.10.3
      API version: 1.22
      Package version: docker-common-1.10.3-46.el7.14.x86_64
      Go version: go1.6.2
      Git commit: 5206701-unsupported
      Built: Mon Aug 29 14:00:01 2016
      OS/Arch: linux/amd64