Object storage, also called object-based storage, is a type of IT storage for unstructured, non-hierarchical data (such as email messages, documents, videos, graphics, audio files and web pages) known as objects. An object is data bundled with the metadata that describes its contents. Each object is assigned a globally unique ID, and objects are retrieved by applications that present the object ID to object storage. Unlike file systems, where files are stored in folders nested within other folders, objects are stored in a flat (non-hierarchical) structure or pool. Objects may be local or geographically separated. An object is not limited to any type or amount of metadata. Object metadata is user-definable and may include the type of application the object is associated with; the priority of its application; the level of data protection to assign to the object; if the object should be replicated to another site or sites; when to move the object to a different site or storage tier; and when to delete the object.
The main benefit of object storage is flexibility, not performance. Most object storage is based on clusters of commodity servers with internal direct-attached storage. Scaling is simply a matter of adding nodes to the cluster. Data protection may be accomplished by replicating objects to one or more nodes in the cluster. Custom analytics on data use are simple to perform. Object stores are generally easy to manage, can scale almost infinitely, and can carry large amounts of metadata. Although file and block storage provide better performance, the granular metadata and near-infinite scalability make object storage beneficial to organizations that use big data analysis, cloud-based storage or distributed data pools. Object storage is a poor choice for business applications that require rapid and frequent access to data, such as financial systems.
Companies with rapidly growing storage needs that depend on object storage flexibility may use a software-defined storage solution. Software-defined storage separates the physical storage hardware (data plane) from the data storage management logic or “intelligence” (control plane). It requires no proprietary hardware components and can run on off-the-shelf, low-cost x86 hardware. Ceph, the most popular OpenStack software-defined storage solution on the market today, can be scaled from a storage appliance to a cost-effective cloud solution. Ceph provides unified block and object storage plus thin provisioning, erasure coding and cache tiering functionality. SUSE Enterprise Storage is powered by Ceph technology.