October 14, 2021 By IBM Cloud Education 7 min read

A look into file, object and block storage, their key differences and what type best meets your needs.

Your organization’s data is one of its most valuable assets. Each piece of data or larger data sets — customer information, big data analytics, financial information, employee records, custom applications, etc. — requires you to make a crucial decision regarding where and how to store the information. While organizations often employ multiple types of storage, storage decisions should be made on the data level.

What is object storage?

Object storage is a system that divides data into separate, self-contained units that are re-stored in a flat environment, with all objects at the same level. There are no folders or sub-directories like those used with file storage. Additionally, object storage does not store all data together in a single file. Objects also contain metadata, which is information about the file that helps with processing and usability. Users can set the value for fixed-key metadata with object storage, or they can create both the key and value for custom metadata associated with an object.

Instead of using a file name and path to access an object, each object has a unique number. Objects can be stored locally on computer hard drives and cloud servers. However, unlike with file storage, you must use an Application Programming Interface (API) to access and manage objects.

Check out the following video for a deeper dive into object storage:

Pros and cons of object storage

In recent years, many organizations replaced their on-premises tape storage drives with object storage, which increased usability and security. Examples of object storage systems includes SAN, iSCSI and local disks.


  • Handles large amounts of unstructured data: The format of object storage allows for easily storing and managing a high volume of unstructured data, which is becoming increasingly important with artificial intelligence, machine learning and big data analytics.
  • Affordable consumption model: Instead of paying in advance for a set amount of storage space, as is common with file storage, you purchase only for the object storage you need.
  • Unlimited scalability: Because object storage uses a consumption model, you can add as much additional storage as you need — even petabytes or more.
  • Uses metadata: Because the metadata is stored with the objects, users can quickly gain value from data and more easily retrieve the object they need.
  • Advanced search capabilities: Object storage enables users to search for metadata, object contents and other properties.


  • Cannot lock files: All users with access to the cloud, network or hardware device can access the objects stored there.
  • Slower performance than other storage types: The file format requires more processing time than file storage and block storage.
  • Cannot modify a single portion of a file: Once an object is created, you cannot change the object; you can only recreate a new object.

Use cases for object storage

  • IoT data management: The ability to quickly scale and easily retrieve data makes object storage a good choice for the rapidly increasing amounts of IoT data being gathered and managed, especially in the manufacturing and healthcare industries.
  • Email: Organizations that are required to store large volumes of emails for historical and compliance purposes often turn to object storage as their primary repository for both scalability and price.
  • Backup/recovery: Organizations often turn to object storage for their backup and recovery storage because performance is less of an issue for this use case.  
  • Video surveillance: Object storage provides an affordable option for organizations that need to store many video recordings and keep the footage for several years.

What is file storage?

File storage is when all the data is saved together in a single file with a file extension type that’s determined by the application used to create the file or file type, such as .jpg, .docx or .txt. For example, when you save a document on a corporate network or your computer’s hard drive, you are using file storage. Files may also be stored on a network-attached storage (NAS) device. These devices are specific to file storage, making it a faster option than general network servers. Other examples of file storage devices include cloud-based file storage systems, network drives, computer hard drives and flash drives.

File storage uses a hierarchical structure where files are organized by the user in folders and subfolders, which makes it easier to find and manage files. To access a file, the user selects or enters the path for the file, which includes the sub-directories and file name. Most users manage file storage through a simple file system, such as File Manager.

The following video provides a closer look at both file and block storage:

Pros and cons of file storage

Examples of data typically saved using file storage include presentations, reports, spreadsheets, graphics, photos, etc. File storage is familiar to most users and allows access rights and limits to be set by the user but managing large numbers of files and hardware costs can become a challenge.


  • Easy to access on a small scale: With a small-to-moderate number of files, users can easily locate and click on a desired file, and the file with the data opens. Users then save the file to the same or a different location when they’re finished with it.
  • Familiar to most users: As the most common storage type for end users, most people with basic computer skills can easily navigate file storage with little assistance or additional training.
  • Users can manage their own files: Using a simple interface, end users can create, move and delete their files.
  • Allows access rights/file sharing/file locking to be set at user level: Users and administrators can set a file as write (meaning users can make changes to the file), read-only (users can only view the data) or locked (specific users cannot access the file even as read only). Files can also be password-protected.


  • Challenging to manage and retrieve large numbers of files: While hierarchical storage works well for, say, 20 folders with 10 subfolders each, file management becomes increasingly complicated as the number of folders, subfolders and files increases. As the volume grows, the amount of time for the search feature to find a desired file increases and becomes a significant waste of time spread over employees throughout an organization.
  • Hard to work with unstructured data: While it’s possible to save unstructured data like text, mobile activity, social media posts and Internet of Things (IoT) sensor data in file storage, it is typically not the best option for unstructured data storage, especially in large amounts.
  • Becomes expensive at large scales: When the amount of storage space on devices and networks reaches capacity, additional hardware devices must be purchased.

Use cases for file storage

  • Collaboration of documents: While it’s easy to collaborate on a single document with cloud storage or Local Area Network (LAN) file storage, users must create a versioning system or use versioning software to prevent overwriting each other’s changes.
  • Backup and recovery: Cloud backup and external backup devices typically use file storage for creating copies of the latest versions of files.
  • Archiving: Because of the ability to set permissions at a file level for sensitive data and the simplicity of management, many organizations use file storage for archiving documents for compliance or historical reasons.   

What is block storage?

Block storage is when the data is split into fixed blocks of data and then stored separately with unique identifiers. The blocks can be stored in different environments, such as one block in Windows and the rest in Linux. When a user retrieves a block, the storage system reassembles the blocks into a single unit. Block storage is the default storage for both hard disk drive and frequently updated data. You can store blocks on Storage Area Networks (SANs) or in cloud storage environments.

Pros and cons of block storage

Block storage systems have been a mainstay in the tech industry for decades. However, many organizations are transitioning away from block because of the limited scale and lack of metadata.


  • Fast: When all blocks are stored locally or close together, block storage has a high performance with low latency for data retrieval, making it a common choice for business-critical data.
  • Reliable: Because blocks are stored in self-contained units, block storage has a low fail rate.
  • Easy to modify: Changing a block does not require creating a new block; instead, a new version is created.


  • Lack of metadata: Block storage does not contain metadata, making it less usable for unstructured data storage.
  • Not searchable: Large volumes of block data quickly become unmanageable because of limited search capabilities.
  • High cost: Purchasing additional block storage is expensive and often cost-prohibitive at a high scale.

Use cases for block storage

  • Databases: Because block storage has a high performance and is easily updatable, many organizations use it for transactional databases.
  • Email servers: High performance and reliability make block storage a common solution for storing emails.
  • Virtual machine file system (VMFS) volumes: Organizations often use block storage for deploying VMFS across the enterprise. Take, for example, the deployment of virtual machines across an enterprise. With block storage, you can easily create and format a block-based storage volume to store the VMFS. A physical server can then attach to that block, creating multiple virtual machines. What’s more, creating a block-based volume, installing an operating system and attaching to that volume enables users to share files using that native operating system.

What are the key differences between object storage, block storage and file storage?

When determining which type of storage to use for different types of data, consider the following:

  • Cost: Because the costs involved with block and file storage are higher, many organizations choose object storage for high volumes of data.
  • Management ease: The metadata and searchability make object storage a top choice for high volumes of data. File storage, with its hierarchical organization system, is more appropriate for lower volumes of data.
  • Volume: Organizations with high volumes of data often choose object or block storage.
  • Retrievability: Data is relatively retrievable from all three types of storage, though file and object storage are typically easier to access.
  • Handling of metadata: Although file storage contains very basic metadata, information with extensive metadata is typically best served by object storage.
  • Data protection: While the data is stored, its essential the data is protected from breaches and cybersecurity threats.
  • Storage use cases: Each type of storage is most effective for different use cases and workflows. By understanding their specific needs, organizations can select the type that fits the majority of their storage use cases.

The future of storage

As organizations continue their digital transformations and increase their use of AI and machine learning, the volume of data will continue to increase at a rapid rate, which makes storage a top priority.

The type of storage selected affects the cost of the storage and how easily you can access the data in the future. Organizations must understand the types of storage that are available, and then evaluate their data needs to select the most appropriate storage type.

As new data types and uses arise, organizations must constantly evaluate and optimize their storage types for each subset of data. Storage strategy and decisions should continually evolve as business needs and technology changes.

IBM and common storage types

IBM offers several storage solutions that enable organizations of all sizes and industries to meet their storage needs.

  • IBM Object Storage reduces costs and downtime while strengthening the developer team and creating new business value.
  • IBM Block Storage provides smart and safe management against data loss at its global data centers with flexible customization and predictable billing.
  • IBM File Storage simplifies storing and enter data.
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