Object storage

Swift was one of the first two services in OpenStack, and object storage was the original mechanism for persistence within OpenStack (and Amazon) clouds. As OpenStack has been adopted for more and more traditional workloads, object storage has lost a lot of its relevance. In fact, many of the OpenStack deployments that we work on in the Enterprise space don't include object storage in the initial release.

An easy way to take an if you build it they will come approach to object storage is to leverage it for storing Glance images. Although a few of your tenants may come to your OpenStack deployment with applications that can persist their data over an S3-compatible interface, almost all of them can use the snapshot capability in Nova to improve their experience on the platform. Storing Glance images in Swift makes them highly available and provides an opportunity to colocate them with the compute infrastructure, dramatically improving network performance.

Object storage backend selection is highly dependent on block and ephemeral storage selection. If you are using Ceph for block storage, using Ceph for object storage greatly simplifies administration of the platform. NetApp provides an integration with Swift, and it may be advantageous to choose it instead if using NetApp for block storage. Swift is also the default object storage provider in OpenStack, and it makes sense to use it in heterogeneous environments from that perspective. In our experience, object storage backends are not subjected to the same kind of scrutiny as block storage backends in the storage selection process. This may be because many object storage systems are less about performance and more about low-cost options to store frequently read data versus a lot of heavy I/O.