# Storage components

This section includes storage components that are required for the NGS-optimized solution for RHOCP.

# HPE CSI Driver for HPE Alletra Storage

The HPE Container Storage Interface (CSI) Driver for Kubernetes is a multi-vendor and multi-platform driver that adds and configures platforms using a component, known as the Container Storage Provider (CSP). The lineage of the HPE Alletra platforms stem from Nimble Storage for HPE Alletra 6070.

HPE CSI was developed as a standard for exposing block and file storage systems to containerized workloads on Container Orchestrator Systems (COS) like Kubernetes. This standard is an initiative to unify the COS storage interface with the storage vendors. For example, a single HPE CSI implemented for a storage vendor is guaranteed to work with all COS.

# HPE CSI Driver architecture

Figure 5 is a diagrammatic representation of the HPE CSI Driver architecture:

FIGURE 5. HPE CSI Driver architecture

# CSI Deployment Workflow

FIGURE 6. High-level flow diagram for HPE CSI Driver deployment on RHOCP 4.12

The Red Hat OpenShift Container Platform (RHOCP) 4.12 cluster includes physical master and worker nodes running RHEL 8.6 as the operating system. The iSCSI interface configured on the host nodes establishes the connection with the HPE Alletra array to the cluster. After the successful deployment of HPE CSI Driver, CSI controller, 3PAR CSP, and Nimble CSP are deployed to communicate with the HPE Alletra arrays via REST APIs. The associated features on Storage Class such as CSI provisioner, CSI attacher, and so on are configured on the Storage Class.