Perhaps storage is not the first thought you have when thinking about adopting a container orchestration solution, such as OpenShift Container Platform. However, if the applications that you might run in containers are stateful, storage is an aspect that you will need to consider at some point. If you have containerized or virtualized applications that demand I/O performance such as databases or messaging queues, you do not want the persistent storage they might require to become a bottleneck in your deployment. Here there can be storage hardware and architecture choices that you can make to limit bottlenecks and maximize performance. But when it comes to flexibility, resiliency, and scalability, considering software-defined storage (SDS) will likely be a factor in your deployment planning. Here too, you do not want your SDS choice to slow your applications down.
If your choice of storage offerings within OpenShift leads you to persistent storage using the Container Storage Interface (CSI), this is where LINSTOR® can enter the picture. LINSTOR is an open source software-defined storage configuration management system, designed for Linux systems. By using LINSTOR, you can define your storage resources abstractly and manage and monitor those resources through OpenShift. Abstracting storage gives you the flexibility to change or scale your physical storage back ends to adapt to business changes, customer demands, or environmental factors, without having to disrupt or change the applications that consume the storage, or how your users interface with different storage back ends.
Replicating persistent storage for high availability
Although it is not a strict requirement, LINSTOR is often used to manage DRBD® replicated storage and makes deploying such storage easier. In particular, LINSTOR uses DRBD 9 for replicating storage resources across your deployment. DRBD is the long-standing open source data replication technology that provides exceptional performance, as LINBIT® testing has shown, as confirmed by independent testing here and here, and as businesses and organizations that use DRBD worldwide have attested. Using DRBD 9 opens up such LINSTOR features as self-healing by configuring automatic replica placement counts, and the DRBD quorum feature to prevent data divergence (so-called split-brains).
Getting started with LINSTOR in OpenShift
LINSTOR is adaptable to different kinds of deployments: bare metal, cloud, or hybrid installations, and it integrates with many platforms. One popular LINSTOR integration is with Kubernetes. LINSTOR also integrates with OpenShift.
A LINSTOR Operator makes it easy to deploy LINSTOR in OpenShift and provides benefits such as high availability (HA) and disaster recovery (DR) capabilities for your Persistent Volume Claims (PVCs). To get you started quickly, you can follow the instructions in the OpenShift Persistent Storage Using LINSTOR Quick Start Guide. This how-to guide will take you through the steps to install LINSTOR in OpenShift, and provides some initial guidance for using LINSTOR within OpenShift.
By following this guide, you can use LINSTOR within an OpenShift cluster, to offer and manage persistent storage for your applications and services. A benefit of this integration will be the ability to dynamically provision highly available, persistent storage volumes for your OpenShift deployments. As an example use case, the guide has instructions for deploying a simple NGINX-based website within OpenShift that will use a persistent volume claim, backed by LINSTOR managed storage. Not only will the deployment in OpenShift make the NGINX instance itself resilient, but by using LINSTOR, the persistent storage used for NGINX data will be highly available across the nodes in your cluster, by virtue of DRBD’s high performance block-level replication. Diving deeper into LINSTOR, you can also explore other benefits such as snapshot shipping for thin LVM or ZFS volumes, to other LINSTOR clusters or to S3 compatible object storage, a feature which can be a part of your disaster recovery planning.
Using an operator to easily deploy LINSTOR in OpenShift
This getting started guide uses the LINSTOR Operator v2 to make deploying LINSTOR in OpenShift even easier. By using LINBIT customer or evaluation account credentials, you can access the LINBIT container images registry. You are then just a kustomization file and a single kubectl
or oc
command away from deployment.
If you are not a LINBIT customer but want to evaluate LINSTOR in OpenShift, contact the LINBIT team to request an evaluation.