Storage Comparison: Object vs. File vs. Block Storage

In today’s increasingly digitized world, more and more storage solutions are introduced. Each storage solution comes with a unique set of characteristics, which fit different use cases. While having options is a good thing, the downside is that you need to spend more time assessing each option. To help you choose the right storage for your data, this article reviews and compares three of the most popular storage options – object storage, file storage, and block storage.

What Is Object Storage?

Object storage is a method that enables you to manage storage in discrete units or objects. When you use this storage type, your data objects are kept in a single repository with no nested or hierarchical file structure.

Each object in your storage contains all the blocks of data that make up your file along with any associated metadata. This data is then placed into a storage pool, a flat address space. When you need to retrieve data, it is located by a unique identifier assigned to that object.

Object storage is useful in part because of the metadata that is attached to files. This metadata can be generated automatically or defined by you, enabling a wide variety of analytics. Another benefit is the ability to flexibly store data without concern for hierarchy. This grants a greater ability to use storage resources to their maximum capacity as well as easier scaling.

Despite these benefits, object storage does have the disadvantage of being slower than file or block storage systems. This makes it a poor choice for applications or workloads that require low latency.

What Is File Storage?

File storage is a method of storing data in a hierarchical system. File storage is the standard method of storage that most users are familiar with. With file storage, your data is stored in the same format it is retrieved in. You can access file storage through the Server Message Block (SMB) protocol in Windows or the Network File System (NFS) protocol in Unix or Linux.

SMB and NFS are protocols that enable you to store files on your server in the same manner as data is stored on a client computer. You can mount all or part of your file system and share access across multiple client devices. These protocols are also commonly used with network-attached storage (NAS) devices.

NAS devices are often used to scale file storage and may also be used in the form of NAS backups, used to provide redundancy for file storage. These devices make it possible to scale file storage, which is otherwise limited to individual disks or physically connected storage devices.

What Is Block Storage?

Block storage is a method that abstracts storage on a low-level storage device. Block storage devices are managed as a cluster of units called blocks. In each block, you store a portion of a single file. This block is then assigned a unique address, enabling files to be spread across multiple machines for more efficient storage use.

When you want to retrieve a file, a request is made to the block device your file is stored on. Once the request is translated to a block request, the reassembled file is returned to your machine, just as if the device was a standard hard drive.

The benefit of block storage is that it enables low-latency operations on a volume that functions like a plug-n-play storage disk. When you attach block storage to your services, you can format it to accept any file system you need, including NTFS, XFS, or ext4. Blocks are also typically duplicated across devices, ensuring that data is recoverable if one device is corrupted.

File vs. Block Storage

With block storage, operations happen in specific blocks based on filing requests sent to the storage server. This requires looking up storage locations for blocks, retrieving those blocks, and returning individual bytes of the file.

With file storage, requests are sent through user-level data representation interfaces. These interfaces require users to specify file information, including file name, URL, and directory location. This requires more from the user but eliminates the need for the storage system to search for or convert the file.

The primary benefit of file storage over block storage is the familiarity that users have with file systems. In contrast, block storage provides significantly greater flexibility than file storage. It can also be modified for performance, while file storage is less customizable. 

In general, file storage is better for creating a content repository for office use or directories, storing smaller amounts of structured data, or storing files with strong data protection requirements. Meanwhile, block storage is better for databases, data storage for mission-critical applications, and storage for virtualized systems.

Object Storage vs. Block Storage

The primary difference between object and block storage is that object storage includes metadata, while block storage doesn't. This enables object storage to include context about files while block storage is contextless. Additionally, in object storage, each object has a unique identifier, eliminating the need to search for data by location as in block storage.

While both block and object storage can be expanded, object storage is more and more easily scalable. To scale object storage, you need only to add more nodes to your storage cluster. In contrast, depending on the block service you are using, you may not be able to scale after your allotted storage is reached.

While object storage provides greater flexibility and customizability to storage is slower than block storage. This is at least partially because block storage enables you to modify incremental parts of your files. Meanwhile, object storage requires objects to be modified as a single unit. This means that any small change you make requires the entire object to be rewritten. This is much slower since it requires more data to be accessed and updated than with block methods.

In general, block storage is better for applications and workflows that rely on storage performance, storage of transactional data, and data that doesn’t require metadata analysis. Meanwhile, object storage is better for storing unstructured data, storing large data sets, and storing data with custom data preservation, deletion, and retention policies.

Conclusion

Typically, there is no right or wrong storage option. What you need to assess is whether this storage option fits your current needs.

Object storage stores data in discrete units or objects and this enables you to store data without any nested or hierarchical file structure. If you do want to create a hierarchical system, you can use file storage. Block storage, on the other hand, enables you to create block units and serve them across multiple machines.

To further understand which storage type is right for your data, you can take a look at use cases and study cases and learn how others are leveraging each solution.