Object storage and file storage are two common methods for storing data, but they have some key differences. Object storage is better suited for certain modern applications, offering greater scalability, flexibility, and cost savings compared to traditional file storage.
What is object storage?
Object storage manages data as objects rather than files in a hierarchical folder structure. Each object contains the data itself, metadata describing the data, and a unique identifier. Objects are stored in a flat address space rather than a file folder hierarchy.
With object storage, the data is broken into discrete units called objects. Each object can be individually addressed and accessed independent of other objects. Objects are organized into containers for access control and billing purposes but do not have a traditional directory hierarchy.
Benefits of object storage
- Scalability – Object storage systems scale seamlessly by adding nodes.
- Durability – Objects are redundantly distributed across nodes to ensure durability.
- Availability – Objects are available as long as a minimum number of nodes are online.
- Flexibility – Objects can have arbitrary metadata applied by the client.
- Cost Savings – Object storage can leverage cheap commodity infrastructure.
What is file storage?
File storage organizes data in a hierarchical tree structure called a file system. The file system arranges data in directories and files. Each file contains the data content plus metadata about the file including name, size, type, creation date, and permissions.
Files are accessed by their path name, which reflects their place in the storage hierarchy. Changing the path to a file by moving it within the hierarchy does not change the file content but changes its access location.
Characteristics of file storage
- Hierarchical structure – Files are organized into folders and subfolders.
- File access – Files are accessed by path name based on storage location.
- File management – The file system manages creation, movement, and deletion of files.
- Limited metadata – Files have a limited set of defined metadata attributes.
- Block storage – File systems are typically built on block storage technologies.
Scalability
One of the key advantages of object storage over file storage is improved scalability. Object storage systems are designed to scale seamlessly by adding inexpensive commodity servers. In contrast, file storage systems have more difficulty scaling capacity and performance linearly.
Object storage systems deal with explosive data growth by distributing data across large numbers of specialized storage nodes. Simply adding more nodes allows the object store to grow capacity and serve more requests in parallel. This horizontal scaling model results in linear scalability in both capacity and performance.
Meanwhile, traditional file storage systems rely on vertical scaling by using more capable storage hardware. However, specialized high-end hardware can become quite expensive. In addition, the network and storage controllers can become bottlenecks that limit overall system capacity and performance.
Advantages of object storage scalability
- Pay-as-you-grow model – Add capacity when needed by adding nodes.
- Elastic performance – Add nodes to improve throughput and operations per second.
- No disruption – Object stores don’t have to rebuild when expanding capacity.
- Cost efficient – Leverage lower cost commodity infrastructure.
Durability and Availability
Objects in object storage systems are designed for high durability and availability using techniques like erasure coding and geographic distribution.
Object storage systems spread objects redundantly across different nodes and often different physical facilities. This distribution ensures objects are still available even with server outages or disk failures. Storing redundant object copies in diverse locations also guards against localized disasters.
Erasure coding further reduces storage overhead compared to traditional replication while providing equivalent durability. With erasure coding, objects are broken into data fragments with checksum fragments added. These encoded fragments are distributed across different nodes so the original object can be reliably reconstructed from fewer fragments.
In comparison, file storage systems rely on techniques like RAID, backups, and high availability storage controllers for redundancy. However, these approaches may incur more storage overhead and have greater risk of simultaneous failures impacting availability.
Benefits of object storage durability and availability
- Erasure coding – Provides durability efficiently using less redundant storage.
- Geographic distribution – Spreads copies across facilities to mitigate localized failures.
- Automatic repair – Disturbed objects are automatically replicated from redundant copies.
- Fewer single points of failure – Objects persist independently of failed nodes or disks.
Flexibility
Object storage provides greater flexibility than file storage in how metadata can be associated with data. Users can define arbitrary custom metadata headers when storing objects.
Having custom metadata enables new use cases and makes object storage a more flexible building block. For example, a music service could include metadata on genre, artist, album, and song title when storing music files as objects. A photo service could include metadata on time, location, people, and activity.
This flexible metadata empowers richer searching, filtering, and organization. The metadata becomes queryable fields for an object database without having to crack open file contents.
In contrast, file storage has limited built-in metadata like filenames, timestamps, and permissions. Expanding metadata generally requires separate databases indexed to files which must be remained in sync.
Object storage metadata advantages
- Custom metadata – Objects include arbitrary user-defined metadata.
- Indexed metadata – Metadata is indexed for searchability without opening objects.
- Contextual metadata – Metadata reflects object contents vs just filenames.
- Persistent metadata – Metadata remains with objects when copied between containers.
Cost Savings
Object storage built on commodity infrastructure can provide significant cost savings compared to enterprise file storage systems.
Enterprise file storage relies on high-end proprietary hardware and specialized storage controllers. These expensive components help deliver performance but result in poor utilization and require overprovisioning capacity.
Meanwhile, object storage maximizes low-cost commodity infrastructure like servers, disks, and Ethernet networking. Small object sizes allow fine-grained load distribution across many nodes. Intelligent software manages redundancy, integrity, and load balancing without specialized hardware.
The radically simpler storage nodes and shared-nothing distributed architecture minimize costs. High utilization further improves the economies of scale from aggregating inexpensive components.
How object storage reduces costs
- Commodity infrastructure – Uses lower cost commodity servers and disks.
- Storage efficiency – High utilization due to distributed architecture.
- Incremental scaling – Grow linearly by adding nodes as needed.
- No overprovisioning – Start small and scale out to add capacity.
Use Cases
Object storage is better suited than traditional file storage for emerging modern workloads and scalable web and cloud applications.
Web applications
Object storage is ideal for storing static web content like images, audio, video, HTML, and JavaScript. It simplifies deployments using cheap commodity infrastructure. Dynamic content can be layered on top of the object store.
Cloud applications
Applications built for cloud platforms like AWS, Azure, and Google Cloud can leverage highly scalable object storage services like S3, Blob, and GCS. The object model better matches cloud computing principles.
Data lakes
Object stores provide a scalable repository for aggregating disparate big data before further processing. Metadata can be appended to track data sources and context.
Backups
The distributed nature and infinite scalability of object stores are ideal for large-scale cloud backups and data protection. Redundancy ensures backup integrity while custom metadata adds queryability.
Content repositories
Object storage simplifies building massively scalable and durable content repositories for images, videos, documents, and more. Content remains self-descriptive using attached metadata.
Conclusion
Object storage is better suited than traditional file storage for modern workloads due to superior scalability, flexibility, availability, and cost savings. Object storage should be considered for large-scale web and cloud applications, content repositories, big data analytics, and backups.
Key advantages of object storage include:
- Massive horizontal scalability using commodity infrastructure
- Built-in redundancy for high durability and availability
- Flexible object metadata enabling richer queries
- Lower overall costs due to high utilization
For emerging data-driven applications, object storage provides a more agile, elastic, and cost-efficient storage foundation than legacy file systems.
