Provision Docker Storage on a Dedicated Block Device

Internal

• OpenShift 3.5 Installation

Procedure

Provision an unformatted block device. For this example, it will be referred to as /dev/sdb.

Create one partition that spans the entire device. Either fdisk or sfdisk can be used. This is how the partition is created with fdisk.

The procedure will create a /dev/sdb1 partition.

Erase all signatures from the partition:

Initialize the partition for use by LVM:

Create the volume group, conventionally named "docker_vg", using the partition prepared by the previous steps /dev/sdb1:

Assuming STORAGE_DRIVER=devicemapper. Inquire on STORAGE_DRIVER=overlayfs or STORAGE_DRIVER=overlayfs2. Repeat the procedure? What is the difference in behavior?

Crate the LVM thin pool.

Write /etc/sysconfig/docker-storage:

DOCKER_STORAGE_OPTIONS="--storage-driver device mapper ${dm_fs} --storage-opt dm.thinpooldev=$POOL_DEVICE_PATH $(get_deferred_removal_string) $(get_deferred_deletion_string) ${EXTRA_DOCKER_STORAGE_OPTIONS}"

Continue with /Users/ovidiu/projects/openshift/docker-storage-setup, function: setup_storage()

Verify your configuration. You should have a dm.thinpooldev value in the /etc/sysconfig/docker-storage file and a docker-pool logical volume:

# cat /etc/sysconfig/docker-storage
DOCKER_STORAGE_OPTIONS=--storage-opt dm.fs=xfs --storage-opt
dm.thinpooldev=/dev/mapper/docker--vg-docker--pool

# lvs
  LV          VG   Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  docker-pool rhel twi-a-t---  9.29g             0.00   0.12

Before using Docker or OpenShift Container Platform, verify that the docker-pool logical volume is large enough to meet your needs. The docker-pool volume should be 60% of the available volume group and will grow to fill the volume group via LVM monitoring.