S3 Object Storage vs Block Storage – What is the difference?

Even technically skilled IT administrators do not always understand the business value of object storage. What problems does it solve? Is object storage suitable for particular workloads? What are its shortcomings and limitations? What types of applications work better and what needs to be redesigned to take advantage of the storage technology?

In this article, we will explore object storage, compare it to traditional storage approaches, and give an overview of where it can improve performance.

What is object storage?

S3 Object storage is a way of organizing and working with storage units called objects. Each object contains the following:

Data itself. This is anything from a family photo to a large video archive or database. 

Metadata. It contains contextual information about that data, its purpose, its confidentiality, or anything else relevant to the way the data is used.

Unique identifier – a value assigned to an object so that it can be found in a distributed system. Thus, you can find data without the need to know its physical location (which may be in different parts of the data center or different parts of the world).

Block storage vs. object storage

In block storage, files are organized as data blocks of the same size, each with its address, but with no additional information. Block storage is used in most corporate workloads and has a wide range of applications.

In object storage, entire blocks of data are stored within an object that contains data, metadata, and a unique identifier. There is no limit to the type or amount of metadata, which makes object storage powerful and flexible. In an enterprise data center, object storage is used for data that needs to be highly accessible and persistent.

Unlike block storage, object storage does not offer the ability to incrementally edit a single part of a file. Objects have to be managed as a single unit, which requires accessing the whole object. 

In addition, block storage can be directly accessed by the operating system as a mounted disk volume, whereas object storage cannot achieve this without significant performance degradation.

S3 Object storage is suitable for unstructured data sets such as backups, static web content, archived multimedia files (videos, images, or music). It is also a perfect tool for storage solutions that involve analytics, CDNs, and geo-distributed data preservation. 

Since block storage devices are accessible as volumes and are directly accessed by the operating system, structured database storage, random read/write, and virtual machine file system (VMFS) volumes are good examples of the use of such storage systems.

Why opt for S3 Object Storage?

The use of cloud object storage is increasing for many reasons. Primarily, there is more and more data, generated every day, and object storage provides speed, scalability, robustness, security, data integrity, and reliability. Object storage is the most effective underlying technology for applying data analytics.

Traditional systems often experience problems with scaling. Objects such as static web content, backups, and archives are great use cases for object-based storage. Its architecture can be scaled and managed simply by adding more nodes.

In an object-based storage architecture, the metadata sits in the object itself. This means that you do not need to create databases to combine metadata with objects. In addition, custom metadata can be created, modified, and added as necessary. Also, custom metadata simplifies searching and navigating.


IDC estimates that by 2025 we will have five times more data than we have now, and 80% of all data generated is unstructured. Since that growth can be unpredictable, the storage solution must be able to scale quickly and effortlessly on demand. S3 Object storage allows enterprises to not only store data better, but also to improve management, search and therefore use it to gain deeper insights.

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author: Yusuf Ozturk
published: 12/27/2021
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