• Storage drives:
  • Hard disks or hard disk drives (HDDs): Hard disk drives (HDDs) provide storage capacity for a NAS unit and an easy way to scale. As the need for data storage space increases, users can add additional hard disks to meet the system demand—known as “scale-out” NAS. More modern systems use flash storage with HDDs or as a stand-alone configuration. The use case for the NAS device usually determines the type of HDD. For example, sharing large media files across an organization requires more resources than a file system for a single user at home.
  • Solid-state drives (SSDs): While most NAS devices have HDDs, solid-state drives (SSDs)—semiconductor-based storage devices that typically use NAND flash memory to save persistent data—are a better choice for speed and high performance.

• Network: One or multiple networked NAS devices are connected through a local area network (LAN) or an Ethernet network with an assigned IP address.

• Network protocols: Transmission Control Protocol/Internet Protocols (TCP/IPs) enable data transfer, but the network protocols for data sharing can vary based on the type of client. For example, a Windows client typically has a server message block (SMB) protocol, while a Linux or UNIX client has a network file system(NFS) protocol.

• Central processing unit (CPU):  All NAS devices contain a CPU that manages the file system, reads and writes data, and processes and serves files.

• Operating system: While standard operating systems can handle thousands of requests, NAS relies on a lightweight OS that restricts the system to two requests: data storage and file sharing. 

• Networking interface: A NAS device relies on a network connection (Ethernet cable or wifi) through the networking interface. Some NAS devices have USB ports for direct computer connections with desktops, mobiles and other devices.

Scale-out FBS, or scale-out NAS, refers to the addition of hard disks to expand storage capacity. According to an IDC study, 41% of respondents have deployed 40%+ apps and workloads on scale-out FBS within a data center. This research also indicates that the workloads for this storage system will continue to grow in parallel with public cloud file-based services.² However, scale-out FBS is particularly appealing due to its cost compared to other storage providers. 

By combining NAS and SAN storage architecture, NAS gateways help address some of the limitations of legacy NAS. While NAS can scale by adding more hard disk drives, the new disks need to be introduced to the network, requiring file references to undergo remapping on the new drives. NAS gateways split the storage system, allowing individual servers to scale independently of one another. 

The different types of available NAS systems are also defined by their user base, whether in an enterprise, small business or consumer NAS setting.

High-end NAS devices have enough disks to support a redundant array of independent disks (RAID) configuration, which combines multiple hard disk drives in a RAID bay to increase performance and protect data if a NAS drive fails. 

This type of NAS system targets the at-home user who needs centralized file storage accessible to multiple workers through routers, PCs and mobile devices. Consumer NAS can also operate as a file server (storage server), print server, backup system and multimedia server. A study from 360 Research Reports projects this segment to grow in the US at a CAGR of 7.3% between 2021 and 2027.³

Unlike a NAS system, which is connected to a network, a DAS device typically attaches to a computer. DAS can also connect to an external drive through a USB or Thunderbolt cable, although it is not as common.

While DAS devices are low in cost and easy to configure, they have limited scalability. Since storage is not accessible through a network, the number of available external ports restricts file access. Moreover, DAS systems can become more costly to back up as organizations grow in size. 

Storage area network (SAN) systems differ from NAS by providing block-level storage versus file-level storage. SAN systems are also distinguished by their use of high-speed networks such as Fibre Channel to provide data access to the storage unit.

Also, while NAS uses a single device comprising redundant storage containers or RAID, SAN storage uses a network of devices, including SSD and flash storage, cloud storage and more.

Structured transactional workloads are typically handled by SAN systems, while unstructured workloads are typically managed by NAS deployments. Finally, SAN setups can be more costly and complicated.