Network Attached Storage, NAS

NAS (Network Attached Storage) is a freestanding integrated disk system. NAS server, with its specialized OS and a set of useful functions for quickly starting the system and providing access to files. The system connects to a conventional computer network (LAN), and is a quick solution to the problem of lack of free disk space available to users of this network.

NAS is a storage that connects to the network like any network device, provides file access to data. NAS devices are a combination of DSS and the server to which it is connected. In the simplest version, a NAS device is a regular network server that provides file resources.

History

The development of network technologies has led to the emergence of two network solutions for DSS of systems - Storage Area Network (SAN) for block-level data exchange supported by client file systems, and servers for storage at the file level Network Attached Storage (NAS). To distinguish traditional storage from network DSS, another retronym was proposed - Direct Attached Storage (DAS).

The successive DAS, SAN, and NAS on the market reflect the evolving chains of communication between applications using data and the bytes on the media containing this data. Once the application programs themselves read and wrote blocks, then drivers appeared as part of the operating system. In modern DAS, SAN and NAS, the chain consists of three links: the first link is the creation of RAID arrays, the second is the processing of metadata that allows you to interpret binary data in the form of files and records, and the third is services for providing data to the application. They differ in where and how these links are implemented. In the case of DAS, the DSS be "bare"" it only provides the ability to store and access data, and everything else is done on the server side, starting with interfaces and a driver. With the advent of SAN, RAID is transferred to the DSS side, everything else remains the same as in the case of DAS. And NAS differs in that metadata is also transferred to the DSS to provide file access, here the client can only support data services.

SAN became possible after Fibre Channel (FC) was developed in 1988 and ANSI was approved as a standard in 1994. The term Storage Area Network dates from 1999. Over time, FC gave way to Ethernet, and iSCSI-connected IP-SANs became widespread.

The idea of ​ ​ a NAS network storage server belongs to Brian Randell from the University of Newkastle and was implemented in machines on a UNIX server in 1983. This idea was so successful that it was picked up by many companies, including Novell, IBM, and Sun, but ultimately replaced the leaders of NetApp and EMC.

In 1995, Garth Gibson developed the principles of NAS and created Object Storage (OBS) DSS. He began by dividing all disk operations into two groups, one including more frequently performed ones, such as reading and writing, and another rarer one, such as name operations. Then he offered in addition to blocks and files another container, he called it an object.

OBS is distinguished by a new type of interface, it is called object. Client data services interact with metadata over an object API API. OBS not only stores data, but also supports RAID, stores metadata related to objects, and supports an object interface. DAS, SAN, NAS, and OBS coexist in time, but each of the access types more closely corresponds to a specific type of data and applications.

Read more about DSS evolution here.

2024: Global Networked Storage Market Size Reaches $40.33 Billion for the Year

At the end of 2024, sales of networked storage devices (NAS) on a global scale reached $40.33 billion. More than 40% of global costs came from the North American region. Such data are provided in a Fortune Business Insights study, the results of which TAdviser reviewed in early June 2025.

One of the market drivers is the rapid growth of information, for the secure storage and backup of which NAS solutions are increasingly used. Such devices provide a number of advantages over cloud services. In particular, NASs do not require a monthly fee for the amount of data stored, while providing more ways to access files. You can interact with NAS through smartphones, tablets and personal computers. In addition, such vaults allow you to share files and share the device with other users.

The NAS design provides for the presence of its own processor and RAM, as well as the use of its own operating system. This enables a wide range of features from automatic file backup and protection to media collections and streaming music, photos, and videos. Moreover, to copy large amounts of data, you can connect directly to the network storage, bypassing transmission via the Internet or an internal Wi-Fi network.

The integration of functions based on artificial intelligence has a positive impact on the industry. For example, AI algorithms can serve to automatically arrange thousands of photos recorded on NAS drives: neural networks perform face recognition, object identification and geotagging. In addition, AI increases the efficiency of searching for certain files: users can make requests in natural language.

Depending on their needs, customers can choose a NAS with the right number of storage bays to create a large storage capacity. In this case, both traditional hard drives and high-speed solid-state products can be installed. Modern NASs support common protocols for accessing files, such as SMB/CIF for working with computers running Windows or AFP for Apple. Many models provide the ability to create RAID arrays to reduce the risk of data loss.

By NAS application, the market is segmented into BFSI (Banking, Financial Services and Insurance), IT & Telecom, Retail, Healthcare, power & Utilities, Public Administration, Media & Entertainment, Education, etc. In 2024, the largest share of revenue was provided by the IT direction - 24.3%. From a geographical point of view, North America leads with 42% of global sales, which corresponds to $16.93 billion. Globally, the list of leading players includes:

• Dell Technologies;
• IBM;
• Hitachi Vantara;
• Western Digital;
• Seagate;
• Qnap Systems;
• NetApp;
• NetGear;
• Synology;
• Buffalo Americas;
• Nasuni;
• Asustor;
• Acronis International;
• Qumulo;
• TerraMaster;
• iXsystems;
• Cloudian;
• LaCie;
• Ciphertex;
• Pure Storage.

In 2025, the NAS market size is expected to reach $46.97 billion. Fortune Business Insights analysts believe that in the future, the CAGR will be 16.6%. Thus, by 2032, sales may increase to $137.21 billion.^[1]

NAS Architecture

NAS devices, often called filers, consist of a single head device that performs data processing and makes a network connection of a chain of disks. NAS devices allow you to use storage systems on Ethernet networks, they use the TCP/IP protocol to organize file sharing. These devices allow clients to share files even if the client systems are running different operating systems. Unlike the DAS architecture, NAS systems do not need to take servers offline to increase overall capacity; disks can be added to the NAS structure by simply connecting the device to the network.

NAS Connection Diagram

NAS technology (Network data storage Attached Storage) is developing as an alternative to universal ones that to servers carry many functions (printing, applications, fax server, email etc.). Unlike them, NAS devices perform only one function - a file server. And they try to do it as best, easier and faster as possible.

NASs connect LAN to and access data for an unlimited number of heterogeneous clients (clients with different operating systems) or other servers. Currently, almost all NAS devices are focused on using protocol-based networks Ethernet (,). Fast Ethernet Gigabit Ethernet TCP/IP NAS devices are accessed using special file access protocols. The most common file access protocols are,, and. CIFS NFS Inside DAFS such servers are specialized ones, such OS as. MS Windows Storage Server

Tolerances and disadvantages

Pluses

• Cheapness and availability of its resources not only for individual servers, but also for any computers of the organization
• Ease of Resource Sharing
• Easy to deploy and administer
• Client versatility (one server can serve MS, Novell, Mac, Unix clients)

NAS devices are very good in a heterogeneous environment where fast file access to data is required simultaneously for many clients, including TCP/IP, CIFS, NFS, FTP, TFTP, etc. It also provides high storage reliability and management flexibility combined with easy maintenance. Since filenames can contain characters from different languages, many NASs provide support for UTF-8, Unicode encodings.

NAS devices can be the simplest "boxes" with one Ethernet port and two hard drives in the RAID1, up to huge systems with a large number of disks and external Ethernet ports, several specialized servers. Sometimes NAS devices are part of a SAN network and do not have their own drives, but only provide file access to data located on block storage devices. In this case, NAS takes on the function of a powerful specialized server, and SAN - storage devices. We get a DAS topology composed of NAS- and SAN-components.

Minuses

• Access to information through "network file systems" protocols is often slower than to a local disk.
• Most low-cost NAS servers do not provide a high-speed and flexible method of accessing data at the block level inherent in SAN systems, rather than at the file level.

The main disadvantage of NAS is the increased load on the network. Several gigabit Ethernet controllers operating in duplex mode are usually used to connect to the network, and although the proper communication speed over the network environment is achieved in this way, the load on the network increases. Therefore, you must first calculate the location and number of NAS devices.

NAS is much less common than SAN devices, but the share of such systems is constantly growing due to the displacement of DAS.

Market estimates

2012

On April 5, 2012, Global Industry Analysts published the Network Attached Storage Devices: A Global Strategic Business Report, which identified the main points and reasons for the growth of online storage architectures. According to the research company, the volume of information in the world is increasing by 65% annually and will reach 3 million petabytes by 2020. The result is a natural increase in investment in data storage and backup.

Especially popular in light of the emerging trend is the NAS architecture. It does not require high maintenance costs and provides high data availability, sufficient performance, end-user transparency, and platform independence.

The global market for NAS solutions will reach $7 billion by 2017. The largest slice of the pie is in North America, but the Asia-Pacific region will also show an enviable annual growth rate of 14.1% in the next six years.

Until recently, NAS was considered the preserve of small and medium-sized businesses, which traditionally have very limited IT budgets. However, the authors of the report note that an increasing number of vendors are starting to develop NAS solutions for the needs of large enterprises.

In the next few years, as cloud technology spreads, the market expects a real boom. At the same time, the proposed solutions will become more technically advanced, which means more attractive for customers. The key areas for development are accessibility, multi-tenancy and safety.

The Global Industry Analysts report includes an analysis of the activities of 80 major and niche players in the NAS market, including Buffalo, Dell, EMC, Isilon Systems, HP, 3Par, HDS, IBM, LSI, NetApp, Netgear, Oracle, SGI.

See also

• Software-Defined Storage (SDS)
• Direct Attached Storage, DAS
• Storage Area Network (SAN)
• DSS Product and Project Catalog
• Data backup

• Andrey Zakharov, Key Storage Systems and Features
• SANs
• NAS - Networked Storage

Notes