Storage options in IBM Cloud Private

Storage options that are available in IBM® Cloud Private.

Overview

IBM® Cloud Private provides various storage technologies for application workload storage. IBM Cloud Private supports all the storage types that are supported by Kubernetes. However, the following storage types are tested and verified in IBM Cloud Private. All the open source storage technologies are provided in IBM Cloud Private and backed by the IBM Cloud Private open source support statement.

Provided Storage types

Following storage types are tested and verified in IBM Cloud Private.

hostPath

A hostPath volume mounts a file or directory from the file system of the host node into your pod.

hostPath volume is generally used for single node testing. If pod scaling happens horizontally across nodes, the same shared information is not available to the pod. hostPath does not support dynamic provisioning.

Network File System

A Network File System (NFS) volume allows an existing NFS share to be mounted into your pod.

NFS volumes are persistent and data can be handed off between pods. NFS can be simultaneously mounted by multiple writers. NFS storage is easy to set up and familiar to most administrators. However, performance can be a concern and no dynamic provisioning is supported.

vSphere

A vSphere volume is used to mount a vSphere Virtual Machine Disk (VMDK) volume into the pod.

When IBM Cloud Private is installed on a VMware vSphere infrastructure and a vSphere Cloud Provider is configured, vSphere volumes can be created for workload pod.

vSphere volumes are persistent though it supports ReadWriteOnce access mode only. So, it might not be a good choice when an application is looking for multiple replicas of the pod and to handle node failover. However, pods that are collocated on same node can use the same volume.

GlusterFS

GlusterFS is a Scale Out Network Attached Storage file system.

GlusterFS is a scalable, distributed file system that provides persistent volume. Provisioning of volume is done dynamically through Heketi. GlusterFS provided by IBM Cloud Private is an open source solution. IBM Cloud Private relies on the open source community to provide bug fixes and improvements, if needed.

Rook Ceph

Rook Ceph is the Ceph distributed storage system that is deployed and managed by Rook operator within IBM Cloud Private.

Ceph is a distributed storage system with multiple storage presentations that include object storage, block storage, and POSIX-compliant shared file system. Ceph in IBM Cloud Private is deployed and managed via Rook. As both Rook and Ceph are open source projects, IBM Cloud Private relies on the open source community to bring improvements and provide bug fixes, if needed.

Minio

Minio is a lightweight, Amazon S3-compatible distributed object storage server.

Minio in IBM Cloud Private is open-sourced object store that is easy to set up and provides existing IBM Cloud Private supported block storage. IBM Cloud Private relies on the open source community to bring new improvements and provide bug fixes, if needed.

IBM Spectrum Scale

IBM Spectrum Scale™ is an enterprise grade cluster file system that provides concurrent access to a single file system or set of file systems from multiple nodes.

Currently, IBM Spectrum Scale volume can be consumed by a pod through hostPath or by mounting as an NFS volume. IBM Spectrum Scale volume can also be consumed by creating storage classes by using IBM Storage Enabler for Containers plug-in. IBM Storage Enabler for Containers plug-in allows IBM block storage systems and IBM Spectrum Scale to be utilized as storage devices for Kubernetes container clusters. For more information, see Installer for IBM Storage Enabler for Containers.

Comparison of storage providers

• Storage options hosted in IBM Cloud Private
  
• Storage options hosted outside IBM Cloud Private
  
• Storage options available as community Helm charts