The commoditization of IT hardware, the rise of cloud platforms, the emergence of hyper-convergence and the lightning-fast speed of non-volatile memory express (NVMe) flash have perhaps masked some of the fundamentals of data storage.

But, at the root, all storage is categorised as either block, file or object, with those terms derived from how data is accessed in each mode. Files, blocks, and objects are storage formats that hold, organize, and present data in different ways, with each one of them having their own capabilities and limitations.

Figure 1: Block vs File vs Object Storage

What is a block storage?

Block storage chops data into blocks, depending on block size defined and stores them as separate pieces. Each block of data is given a unique identifier, which allows a storage system to place the smaller pieces of data wherever is most convenient.

Block storage is often configured to decouple the data from the user’s environment and spread it across multiple environments that can better serve the data. And then, when data is requested, the underlying storage software reassembles the blocks of data from these environments and presents them back to the user. It is usually deployed in storage-area network (SAN) environments and must be tied to a functioning server.

Because block storage doesn’t rely on a single path to data—like file storage does—it can be retrieved quickly. Each block lives on its own and can be partitioned so it can be accessed in a different operating system, which gives the user complete freedom to configure their data. It’s an efficient and reliable way to store data and is easy to use and manage. It works well with enterprises performing big transactions and those that deploy huge databases, meaning the more data you need to store, the better off you’ll be with block storage.

Hence block storage is the go-to option for Alfresco database, irrespective of database choice, whether its MariaDB, MySQL, PostgreSQL, MS SQL or Oracle.

There are some downsides, though, especially when utilizing against content management system with large amount of data. Block storage can be expensive. It has limited capability to handle metadata, which means it needs to be dealt with in the application or database level—adding another thing for a developer or systems administrator to worry about.

What is file Storage:

File storage, also called file-level or file-based storage organizes and represents data as a hierarchy of files in folders. Data is stored as a single piece of information inside a folder, just like you’d organize pieces of papers inside a folder. When you need to access that piece of data, your computer needs to know the path to find it (Beware! it can be a really long, winding path). Data stored in files is organized and retrieved using a limited amount of metadata that tells the computer exactly where the file itself is kept.

Think of a closet full of file cabinets. Every document is arranged in some type of logical hierarchy—by cabinet, by drawer, by folder, then by piece of paper. This is where the term hierarchical storage comes from, and this is file storage. File storage has broad capabilities and can store just about anything. It’s great for storing an array of complex files and is fairly fast for users to navigate.

The problem is, just like with your filing cabinet, that virtual drawer can only open so far. File-based storage systems must scale out by adding more systems, rather than scale up by adding more capacity.

What is an object storage?

Object storage, also known as object-based storage, is a flat structure in which files are broken into pieces and spread out among hardware. In object storage, the data is broken into discrete units called objects and is kept in a single repository, instead of being kept as files in folders or as blocks on servers.

Object storage emerged as a rival to file-access storage for large quantities of unstructured data when scale-out NAS file systems started to creak under the sheer number of files being stored.

Where file-access storage with its hierarchical file structure can get cumbersome as it grows, object storage brings a “flat” structure with equal access to all objects held, making it eminently suitable for large volumes of unstructured data.

There are few things to keep in mind, to be sure.