Docker Server Runtime

Internal

• Docker Server Operations

Process

OpenShift Docker

root  1150  1  0 12:06 ? 00:00:00 /usr/bin/dockerd-current 
    --add-runtime docker-runc=/usr/libexec/docker/docker-runc-current 
    --default-runtime=docker-runc 
    --authorization-plugin=rhel-push-plugin 
    --exec-opt native.cgroupdriver=systemd 
    --userland-proxy-path=/usr/libexec/docker/docker-proxy-current 
    --selinux-enabled 
    --log-driver=journald 
    --signature-verification=false 
    --storage-driver devicemapper 
    --storage-opt dm.fs=xfs 
    --storage-opt dm.thinpooldev=/dev/mapper/docker_vg-docker--pool 
    --storage-opt dm.use_deferred_removal=true 
    --add-registry registry.access.redhat.com

root 1174  1150  0 12:06 ?  00:00:00 /usr/bin/docker-containerd-current 
    -l unix:///var/run/docker/libcontainerd/docker-containerd.sock 
    --shim docker-containerd-shim 
    --metrics-interval=0 
    --start-timeout 2m 
    --state-dir /var/run/docker/libcontainerd/containerd 
    --runtime docker-runc 
    --runtime-args --systemd-cgroup=true

Configuration

/etc/docker

/etc/sysconfig/docker-storage

Strorage

/var/lib/docker

How do I know that the space consumed for images and containers is allocated in the thin pool, on the different physical device, and not in /var/lib/docker on the root filesystem.

If Docker is already running, re-initialize Docker:

This will destroy any containers or images currently on the host.

1. systemctl stop docker
2. rm -rf /var/lib/docker/*
3. systemctl restart docker

If there is any content in /var/lib/docker/, it must be deleted. Files will be present if Docker has been used prior to the installation of OpenShift Container Platform.

Then go to https://docs.openshift.com/container-platform/3.5/install_config/install/host_preparation.html#reconfiguring-docker-storage