In the last few years, OpenStack has been getting amazingly popular, as it's based on software defined on a wide range, whether it's computing, networking, or even storage. And when you talk about storage for OpenStack, Ceph will get all the attention. An OpenStack user survey, conducted in September 2015, showed Ceph dominating the block storage driver market with a whopping 62% usage.
Ceph provides the robust, reliable storage backend that OpenStack was looking for. Its seamless integration with OpenStack components such as cinder, glance, nova, and keystone provides an all in one cloud storage backend for OpenStack. Here are some key benefits that make Ceph the best match for OpenStack:
- Ceph provides an enterprise-grade, feature-rich storage backend at a very low cost per gigabyte, which helps to keep the OpenStack cloud deployment price down.
- Ceph is a unified storage solution for Block, File, or Object storage for OpenStack, allowing applications to use storage as they need.
- Ceph provides advance block storage capabilities for OpenStack clouds, which includes the easy and quick spawning of instances, as well as the backup and cloning of VMs.
- It provides default persistent volumes for OpenStack instances that can work like traditional servers, where data will not flush on rebooting the VMs.
- Ceph supports OpenStack in being host-independent by supporting VM migrations, scaling up storage components without affecting VMs.
- It provides the snapshot feature to OpenStack volumes, which can also be used as a means of backup.
- Ceph's copy-on-write cloning feature provides OpenStack to spin up several instances at once, which helps the provisioning mechanism function faster.
- Ceph supports rich APIs for both Swift and S3 Object storage interfaces.
The Ceph and OpenStack communities have been working closely over the last few years to make the integration more seamless and to make use of new features as they emerge. In the future, we can expect that OpenStack and Ceph will be more closely associated due to Red Hat's acquisition of Inktank, the company behind Ceph; Red Hat is one of the major contributors to the OpenStack project.
OpenStack is a modular system that has a unique component for a specific set of tasks. There are several components that require a reliable storage backend, such as Ceph, and extend full integration to it, as shown in the following diagram. Each of these components uses Ceph in their own way to store block devices and objects. The majority of cloud deployment based on OpenStack and Ceph use the Cinder, glance, and Swift integrations with Ceph. Keystone integration is used when you need an S3-compatible object storage on the Ceph backend. Nova integration allows boot from Ceph volume capabilities for your OpenStack instances.
