Chapter 1. Preparing to deploy OpenShift Data Foundation

When you deploy OpenShift Data Foundation on OpenShift Container Platform using local storage devices, you can create internal cluster resources. This approach internally provisions base services. Then, all applications can access additional storage classes.

Before you begin the deployment of Red Hat OpenShift Data Foundation using local storage, ensure that your resource requirements are met. See requirements for installing OpenShift Data Foundation using local storage devices.

After you have addressed the above, follow the below steps in the order given:

  1. Install Local Storage Operator.
  2. Install the Red Hat OpenShift Data Foundation Operator.
  3. Create OpenShift Data Foundation cluster on bare metal.

1.1. Requirements for installing OpenShift Data Foundation using local storage devices

Node requirements

The cluster must consist of at least three OpenShift Container Platform worker nodes with locally attached-storage devices on each of them.

  • Each of the three selected nodes must have at least one raw block device available to be used by OpenShift Data Foundation.
  • The devices you use must be empty; the disks must not include physical volumes (PVs), volume groups (VGs), or logical volumes (LVs) remaining on the disk.

For more information, see the Resource requirements section in the Planning guide.

Regional-DR requirements [Developer Preview]

Disaster Recovery features supported by Red Hat OpenShift Data Foundation require all of the following prerequisites in order to successfully implement a Disaster Recovery solution:

  • A valid Red Hat OpenShift Data Foundation Advanced entitlement
  • A valid Red Hat Advanced Cluster Management for Kubernetes subscription

To know how subscriptions for OpenShift Data Foundation work, see knowledgebase article on OpenShift Data Foundation subscriptions.

For detailed requirements, see Regional-DR requirements and RHACM requirements.

Arbiter stretch cluster requirements [Technology Preview]

In this case, a single cluster is stretched across two zones with a third zone as the location for the arbiter. This is a technology preview feature that is currently intended for deployment in the OpenShift Container Platform on-premises.

For detailed requirements and instructions, see Configuring OpenShift Data Foundation for Metro-DR stretch cluster.

Note

Flexible scaling and Arbiter both cannot be enabled at the same time as they have conflicting scaling logic. With Flexible scaling, you can add one node at a time to your OpenShift Data Foundation cluster. Whereas in an Arbiter cluster, you need to add at least one node in each of the two data zones.

Compact mode requirements

OpenShift Data Foundation can be installed on a three-node OpenShift compact bare metal cluster, where all the workloads run on three strong master nodes. There are no worker or storage nodes.

To configure OpenShift Container Platform in compact mode, see Configuring a three-node cluster and Delivering a Three-node Architecture for Edge Deployments.

Minimum starting node requirements [Technology Preview]

An OpenShift Data Foundation cluster is deployed with minimum configuration when the standard deployment resource requirement is not met.

For more information, see Resource requirements section in the Planning guide.

1.2. Enabling file system access for containers on Red Hat Enterprise Linux based nodes

Deploying OpenShift Data Foundation on an OpenShift Container Platform with worker nodes on a Red Hat Enterprise Linux base in a user provisioned infrastructure (UPI) does not automatically provide container access to the underlying Ceph file system.

Note

Skip this step for hosts based on Red Hat Enterprise Linux CoreOS (RHCOS).

Procedure

  1. Log in to the Red Hat Enterprise Linux based node and open a terminal.

  2. For each node in your cluster:

    1. Verify that the node has access to the rhel-7-server-extras-rpms repository. 

      # subscription-manager repos --list-enabled | grep rhel-7-server

      If you do not see both rhel-7-server-rpms and rhel-7-server-extras-rpms in the output, or if there is no output, run the following commands to enable each repository: 

      # subscription-manager repos --enable=rhel-7-server-rpms
      # subscription-manager repos --enable=rhel-7-server-extras-rpms

    2. Install the required packages. 

      # yum install -y policycoreutils container-selinux

    3. Persistently enable container use of the Ceph file system in SELinux. 

      # setsebool -P container_use_cephfs on

1.3. Enabling key value backend path and policy in Vault

Prerequisites

  • Administrator access to Vault.
  • Carefully, choose a unique path name as the backend path that follows the naming convention since it cannot be changed later.

Procedure

  1. Enable the Key/Value (KV) backend path in Vault.

    For Vault KV secret engine API, version 1: 

    $ vault secrets enable -path=odf kv

    For Vault KV secret engine API, version 2: 

    $ vault secrets enable -path=odf kv-v2

  2. Create a policy to restrict users to perform a write or delete operation on the secret using the following commands. 

    echo '
path "odf/*" {
  capabilities = ["create", "read", "update", "delete", "list"]
}
path "sys/mounts" {
capabilities = ["read"]
}'| vault policy write odf -

  3. Create a token matching the above policy. 

    $ vault token create -policy=odf -format json