How do object storage, block storage, and file storage work?
Object, block, and cloud file storage work differently. They each use distinct structures, systems, and storage solutions.
Object storage
Object storage stores and manages data as discrete units called objects. An object typically consists of the actual data—such as documents, images, or data values— and its associated metadata. Metadata is additional information about the object that you can use to retrieve it. The metadata can include attributes like the unique identifier, object's name, size, creation date, and custom-defined tags.
Object storage systems use a flat namespace, so objects are stored without the need for a hierarchical structure. Instead, the object’s unique identifier provides the address for the object within the storage system. A hashing algorithm generates the ID from the object's content, which ensures that objects with the same content have the same identifier.
Block storage
Block storage works by dividing data into fixed-sized blocks and storing them as individual units. Blocks range from a few kilobytes to several megabytes in size. They can be predetermined during the configuration process.
The operating system gives each block a unique address or block number, logged inside a data lookup table. The addressing uses a logical block addressing (LBA) scheme that assigns a sequential number to each block.
Block storage allows direct access to individual data blocks. You can read or write data to specific blocks without having to retrieve or modify the entire dataset the block belongs to.
Cloud file storage
Cloud file storage is a hierarchical storage system that provides shared access to file data. It uses a remote infrastructure of servers to store data. The cloud provider maintains the servers and manages data on them. Files contain metadata like the file name, size, timestamps, and permissions.
You can create, modify, delete, and read files. You can also organize them logically in directory trees for intuitive access. Multiple users can simultaneously access the same files. Security for online file storage is managed with user and group permissions, so that administrators can control access to the shared file data.
When should one use object storage, block storage, and file storage?
Object storage is best used for large amounts of unstructured data. This is especially true when durability, unlimited storage, scalability, and complex metadata management are relevant factors for overall performance.
Block storage offers high-speed data processing, low latency, and high-performance storage. Any service that requires fast access to data works well with block storage. For example, real-time analytics, high-performance computing, and systems with many rapid transactions all benefit from block storage.
Cloud file storage is best when users need concurrent access to a shared system of files. Additionally, file-level access control allows you to set up permissions and access control lists (ACLs) to increase security. For example, collaborative work environments that require sharing files between remote teams use file storage.
Summary of differences
object vs. block vs. file storage