Difference Between Object Storage and Block Storage

Users commonly seek the difference between Object Storage and Block Storage. We have good number of publications on this website on object storage to point towards the differences, but often that process was as a part of answering some other question, such as Methods of Encryption in Cloud Object Storage.

Object Storage is newer technology. Object storage has a flat structure where files are usually broken into pieces, spread on the hardware. The data which is broken into units are called objects and is kept (usually) in a single repository. Data kept as files in folders. Object storage volumes are self-contained repository with a unique identifier which allows the object to be found over a distributed system, and there is metadata which describes the data. That metadata includes details like access contingencies. The metadata can also be quite detailed. Object storage has the requirement of application programming interface (API), which is used by most of the clients. Object storage usually delivered following cloud computing model in cost efficient manner. We only pay for what we use. We can scale easily, used in conjuction of public cloud storage. This kind of storage system is good for static data, it can scale up to extremely large quantities of data. Aapplications can easily find the data and object storage is good at storing unstructured data for them. But, there are drawbacks. Object storage does not work well with traditional databases for being slow process and object storage API. Object Storage is good for Big data, Web applications, Backup archives, Geographical distribution.

Now about block storage. Block storage is older and data is cut in to blocks, stored as separate pieces. Here also like object storage there is a unique identifier, allowing to place the smaller blocks of data wherever is convenient. It works over different operating systems – one block can be on Mac, another block can be on Windows.
So it can decouple the data from the user’s environment. It is the underlying storage software which reassembles the blocks of data from and presents them back to the user. They are usually deployed in storage-area network (SAN) and tied to a server. Block storage is faster than file storage — it can be retrieved quickly. It is an efficient, known and reliable way to store data and good for the enterprises with huge databases, big files. But, there are drawbacks. Block storage can be expensive, limited to handle metadata. Block Storage is good for Databases, Email servers, RAID, Virtual machine file systems.

With block-based storage, it is easier to modify files with access to the specific blocks. In object storage, modifying a file means uploading a new revision of the entire file which can significantly impact performance for the enterprise.