What Is Object Storage and When to Use It

Introduction to Object Storage

Object storage is a data storage architecture that manages data as objects, unlike the traditional file system in classic web hosting that uses a directory hierarchy or block storage that works with fixed-size data blocks. Each object in object storage contains the data itself, metadata describing the object, and a unique identifier enabling access to the object without knowing its physical location on disk.

Amazon S3, launched in 2006, popularized the object storage concept and its API became the de facto standard implemented by almost all providers including MinIO, DigitalOcean Spaces, Backblaze B2, Wasabi, and many others. S3 compatibility means an application written for Amazon S3 can work with any compatible provider without code changes. This prevents vendor lock-in and enables easy transitions between providers or using multiple providers simultaneously.

How Object Storage works

Object structure

An object consists of three components. Data is the file content itself, whether image, video, PDF document, or database backup. Metadata are key-value pairs describing the object like content type, creation date, size, and custom attributes you define. A unique key is the path identifying the object within the bucket, for example images/products/laptop-01.webp. Unlike a file system, this path is a flat structure without real directories.

A bucket is a container for objects similar to a root directory. Each bucket has a globally unique name within the provider's region. Access policies are defined at the bucket level or individual object level, controlling who can read, write, or delete objects. Versioning enables keeping all previous versions of an object, providing protection against accidental deletion or modification. Lifecycle rules automatically move or delete objects based on age, reducing storage costs.

Distributed architecture

Object storage systems distribute data across multiple physical disks and servers automatically. Replication ensures each object exists in multiple copies, typically three on different disks or even in different data centers. This provides exceptional durability with a guarantee of 99.999999999 percent called eleven nines. Loss of one disk or even an entire server doesn't affect data availability because it's automatically read from the remaining copy.

Erasure coding is an alternative to replication that provides the same durability with less storage overhead. Instead of storing three complete copies, erasure coding splits the object into fragments and creates parity fragments enabling reconstruction of the original object even if some fragments are lost. This technique typically uses 50 percent less space than triple replication with the same level of data protection.

S3-compatible API

Basic operations

The S3 API is a REST-based HTTP interface with basic operations including PUT for uploading an object, GET for retrieval, DELETE for deletion, HEAD for retrieving metadata without content, and LIST for listing objects in a bucket. Multipart upload enables uploading large files in parts with the ability to resume in case of connection interruption. Presigned URLs generate time-limited links for accessing private objects without exposing credentials.

AWS CLI and SDKs for all popular programming languages facilitate integration. In PHP use the aws-sdk-php library, in JavaScript aws-sdk or newer modular @aws-sdk/client-s3. Python has the boto3 library which is the de facto standard for working with S3. All these SDKs support configuring the endpoint to work with S3-compatible providers instead of AWS, enabling easy transition between providers.

Advanced features

Event notifications send a message to a queue or trigger a Lambda function when an object is created, modified, or deleted. This enables automated workflows like generating thumbnails after image upload, indexing a document in search, or triggering video transcription. Server-side encryption automatically encrypts objects at rest using AES-256 without any change to application code.

Cross-region replication automatically copies objects to a bucket in another region, providing disaster recovery and lower latency for global users. Object Lock prevents modification or deletion of objects during a defined period, which is essential for regulatory compliance in the financial and healthcare sectors. Inventory reports provide periodic overview of all objects with metadata for audit and analysis.

Typical use cases

Media file storage

Web applications generate huge amounts of media files. For storage, consider backup space for critical data like user uploads, product images, video content, and documents. Storing these files on a web server isn't scalable and complicates deployment and backup. Object storage separates media files from the application, enabling horizontal scaling and CDN distribution. WordPress with a plugin like WP Offload Media automatically uploads media to S3 and serves them through CDN.

Backup and archiving

Object storage is ideal for backup because it offers practically unlimited capacity at low cost. Lifecycle rules can automatically move old backups to a cheaper storage class after a defined period. For example, daily backups are kept in the standard class for 30 days and then automatically moved to archive class with a lower price. Versioning ensures that even if the active backup is overwritten, the previous version remains available.

Static website hosting

S3 and compatible services can serve static sites directly from a bucket without need for a web server. This is ideal for documentation, landing pages, single-page applications, and statically generated sites. Combination with CDN like CloudFront or Cloudflare provides global performance at minimal cost. Costs are typically below one dollar per month for a site with moderate traffic.

Data lake and analytics

Object storage is the foundation of modern data lake architectures where raw data from various sources is stored in original format. Tools like Apache Spark, Presto, or AWS Athena can directly analyze data in S3 without need to load into a database. Parquet and ORC formats optimized for columnar reading enable efficient analytical queries on large data sets stored in object storage.

Pricing model

Cost components

Object storage is charged by three components. Storage is charged per gigabyte per month with prices varying from one to three cents for standard class to half a cent for archive classes. API requests are charged per thousand operations with price differences between reads and writes. Egress traffic is charged per gigabyte for data leaving the data center while ingress traffic is usually free.

Alternative providers like Backblaze B2, Wasabi, and Cloudflare R2 offer significantly lower prices than AWS S3. Cloudflare R2 doesn't charge for egress traffic, which can dramatically reduce costs for sites with lots of media content. Wasabi offers a flat-rate model without API request and egress traffic charges at a price of about EUR 6 per terabyte per month. Compare providers based on your specific usage profile because the cheapest provider depends on the ratio of storage, requests, and traffic.

Object Storage vs Block Storage

Key differences

Block storage works at the data block level and behaves like a physical disk with a file system. It provides low latency and high IOPS essential for databases and applications requiring fast random access. Object storage has higher latency, usually tens of milliseconds, but provides practically unlimited capacity and built-in redundancy. Block storage requires pre-defined capacity while object storage grows dynamically.

Use block storage for operating systems, databases, and applications requiring a POSIX file system. Use object storage for media files, backups, logs, and all data accessed sequentially or rarely. Most modern applications use both types — block storage for database and application code, and object storage for user uploads and static content.

Integration with web applications

A modern web application should use object storage for all user uploads. For regular hosting, see our hosting plans and media content. Laravel has built-in S3 support through the Storage facade with simple configuration in filesystems.php. WordPress plugins like WP Offload Media automate the S3 upload process and URL replacement. Next.js and other modern frameworks can use presigned URLs for direct upload from the client side to S3 without going through your server.

At BeoHosting, we provide S3-compatible object storage that easily integrates with your web applications. Our storage is located in Serbia, ensuring low latency for local users and compliance with local data storage regulations. The combination of our hosting for application and object storage for media files provides an optimal balance of performance and cost for sites with large amounts of static content.

Conclusion

Object storage is a fundamental infrastructure component of modern web applications offering practically unlimited capacity, high data durability, and pay-per-use pricing model. The S3-compatible API ensures portability between providers, and the rich ecosystem of tools and SDKs facilitates integration with any platform. For backups, media files, static content, and data lake scenarios, object storage is the optimal choice that scales with your business growth.