Network-attached storage (NAS) refers to centralized file storage that enables multiple users and heterogeneous client devices to retrieve data over a network. NAS devices are dedicated servers that connect to a local area network (LAN) providing file-based data storage services to other devices like computers, servers, and clients on the network.
NAS systems emerged in the 1990s as a convenient method for centralizing file storage and sharing resources over Ethernet networks. They provide easy access to files such as documents, photos, videos, and music. NAS is commonly used in home networks as well as by businesses and organizations. Compared to alternatives like direct-attached storage (DAS) and storage area networks (SANs), NAS enables simpler centralized management and scalability.
Storage Architecture
A NAS system consists of the NAS server hardware and software components. The server hardware typically includes a CPU, memory, internal or external disk drives, and ethernet network ports. The server runs an operating system like linux or a NAS-specific OS, and the NAS software handles file services and storage management (1).
The main benefits of NAS storage architecture compared to other networked storage are (2):
- NAS provides file-level access compared to block-level access of SAN (storage area network) storage.
- NAS storage is connected via standard ethernet networks, making it simpler and cheaper than fibre channel SANs.
- NAS is optimized for file serving workloads like shared drives or backups.
Overall, NAS offers affordable networked file storage that is easier to deploy than alternatives. The file-level access model also makes it simpler for multiple networked devices to share files.
File Sharing
NAS enables file sharing by allowing multiple users and client devices to access files and folders stored on the NAS over a network. This provides centralized data storage and collaboration capabilities. Some of the main protocols NAS uses for file sharing include:
Network File System (NFS) – An open standard protocol developed by Sun Microsystems used primarily for UNIX and Linux systems to share files over a network. As stated on Medium, NFS handles “Modifying file links and directories” and “creates a connection between the client and the remote system to transfer data.”
Server Message Block (SMB)/Common Internet File System (CIFS) – The standard Windows file sharing protocol, allowing computers to read from and write to files on the NAS. As MyCloudWiki explains, SMB is “used with Microsoft Windows systems.”
Apple Filing Protocol (AFP) – Used for file sharing between Macintosh computers. Enables Mac devices to seamlessly access and store files on the NAS.
Other common protocols include FTP, HTTP, rsync, and more. The various protocols make NAS accessible across operating systems and platforms for centralized file storage, backup, and collaboration.
Permissions & Access Control
Access control and permissions are key aspects of NAS security. Permissions determine which users can access files and folders on the NAS and what actions they can take such as read, write, or execute. Most NAS operating systems like Synology DSM provide granular control over permissions.
There are several ways to manage permissions on a NAS:
- User and group permissions – Assign permissions to individual users or groups. For example, give a ‘users’ group read/write access to a shared folder.
- Access Control Lists (ACLs) – ACLs allow assigning permissions to specific users or groups for individual folders and files, not just entire shared folders. This provides more granular control. Synology NAS and QNAP NAS support ACLs.
- Application permissions – Restrict access to NAS applications like file sharing protocols to authorized users and groups.
Using permissions and access control appropriately is critical for NAS security. Tightly restrict access to sensitive data while providing broader access to shared files as needed.
Data Security
Properly securing the data stored on a NAS is critical. One of the most important aspects of NAS data security is encryption. As recommended by Stonefly, NAS devices should use AES 256-bit encryption, which is a military-grade standard, to encrypt data both in transit and at rest. This prevents unauthorized access even if the physical drives are removed.
Another key element is performing regular backups of the NAS data. This protects against data loss due to hardware failure, accidental deletion, malware, or other issues. The backups should be kept separately from the NAS device. Some NAS appliances have built-in backup capabilities to external drives or cloud storage.
Finally, multi-factor authentication should be enabled for admin access to the NAS interface. Relying on just a password is insufficient. Requiring a second factor, such as a code from an authenticator app or USB security key, greatly enhances security.
By leveraging encryption, backups, and multi-factor authentication, organizations can effectively secure the sensitive data stored on NAS devices from compromise.
Network Integration
Connecting NAS to a network is an essential part of setting up the device. NAS storage relies on networking protocols like Ethernet, TCP/IP, FTP, SMB, and NFS to enable communication and file transfers between the NAS and other devices on the network (Massive, 2023). Most NAS systems have an Ethernet port that can be connected to a router or switch using an Ethernet cable. This gives the NAS a connection to the local area network (LAN) and allows other devices like computers, smartphones and tablets to access the files stored on the NAS.
NAS supports common networking protocols like TCP/IP for basic connectivity, as well as SMB and NFS for actual file transfers. The SMB protocol is commonly used for Windows environments, while NFS is more common on Linux and UNIX networks. Users can map NAS folders as network drives for easy access. FTP can also be used for file transfers. The specific protocols supported will depend on the NAS operating system (TechTarget, 2022). Overall, the networking capabilities allow the NAS to operate seamlessly as networked storage within an existing infrastructure.
Usage Examples
NAS devices are commonly used for file storage and sharing in business and home environments. According to Backblaze, some of the most popular NAS use cases include:
File storage and sharing: NAS provides centralized storage for files that need to be accessed by multiple users. This allows easy collaboration and file sharing. NAS enables multiple users to access files simultaneously.
Media servers: A NAS can store large media files like photos, videos, and music. Media files can then be streamed to devices around a home network. Many NAS devices come with built-in apps to facilitate media streaming.
Backups: NAS systems provide a convenient destination for backups from other devices on the network. Backups can be automated to run at scheduled intervals. This provides protection against data loss.
Virtualization: NAS can be used as storage for virtual machines. The virtual machine files are housed centrally on the NAS rather than on local hard drives.
Benefits & Advantages
NAS systems offer a number of benefits for organizations looking to store and share data. Some of the key advantages of NAS include:
More storage capacity – NAS systems are scalable, allowing you to add more storage as needed by just adding hard drives. This makes it easy to increase capacity. (https://www.magnify247.com/10-benefits-nas/)
Data sharing and collaboration – NAS allows files to be easily accessed by multiple users across a network. This facilitates collaboration and data sharing. (https://www.magnify247.com/10-benefits-nas/)
Centralized storage – Rather than siloing data on individual devices, NAS centralizes files in one location on the network for consolidated access and backups.
Flexibility – NAS can be configured with RAID to provide redundancy and protection against drive failures. NAS offers more flexibility than other storage architectures.
Ease of use – NAS systems are designed to be easy to install, manage, and scale, reducing the burden on IT staff. The interface allows users to easily manage files.
Limitations & Disadvantages
NAS systems have some drawbacks that should be considered before implementation. According to TechTarget, one of the biggest cons of NAS is that it may not be reliable enough for mission-critical data or applications that demand high availability. If the NAS fails or goes offline, operations relying on that data will grind to a halt.
NAS can also struggle with performance as data volumes scale up, especially when supporting multiple users concurrently accessing and updating data. The available bandwidth may not be able to keep up with demand. This leads to lag and latency issues. NAS is generally optimized more for high capacity than high performance.
Additionally, NAS offers file-level access rather than block-level access. This means it works well for basic file sharing purposes, but may not suit more complex applications that require lower level control of storage. Databases and email servers often rely on block-level access.
Compared to SAN solutions, NAS provides more limited security capabilities. Features like zoning and LUN masking help lock down SAN environments. NAS permissions tend to be more open and file-based by nature, according to Amazon Web Services.
Conclusion
In summary, NAS (Network Attached Storage) is an important data storage solution that allows multiple devices on a network to access files from a centralized disk capacity. As data storage needs continue to grow, NAS offers scalable and flexible file sharing along with built-in data protection and backup capabilities.
Looking ahead, NAS systems are evolving to meet new demands. Key trends include deeper integration with cloud storage for hybrid scenarios, adoption of flash-based SSD storage for faster performance, and AI-powered capabilities like predictive analytics. However, challenges remain around managing unstructured data and ensuring security.
While NAS has limitations like lack of computational power for intensive workloads, its simple centralized architecture continues to provide substantial benefits for companies needing to store and share files across a network. NAS enables organizations to cost-effectively scale storage while enhancing data protection and collaboration. As long as data growth persists, NAS will likely continue as an essential platform for robust and secure file services.