NAS, which stands for Network-Attached Storage, refers to file-level computer data storage servers connected to a computer network providing data access to heterogeneous clients. Rather than just storing data like a regular external hard drive, NAS devices allow multiple users and client devices to access data simultaneously over a network.
Overview of NAS
A NAS device is essentially a specialized computer built for the sole purpose of file sharing. It is an IP-based server connected to a local area network and assigned an IP address, allowing it to be accessed by any authorized device on the network. The operating system installed on a NAS device is optimized for file storage and sharing.
Some key characteristics of NAS include:
- Provides centralized storage for files, making them easily accessible from many devices on the network
- Allows file sharing between heterogeneous client devices including Windows, Mac, Linux computers, tablets, smartphones etc.
- Offers data redundancy and protection through RAID technology
- Can be accessed locally within a LAN or remotely through the internet
- Manages user access controls and permissions
- Built using commodity hardware components like standard hard drives
Compared to general purpose servers, NAS devices are easier to setup and maintain. The user just has to connect the NAS to the network and configure access. Most NAS operating systems like FreeNAS include a web-based admin console for management.
How NAS Works
On a basic level, NAS works as follows:
- The NAS device is connected to a local area network, either through a wired ethernet connection or WiFi.
- Specialized NAS operating system software is installed on the NAS to handle file transfers and sharing.
- Storage disks (usually hard disk drives) are installed in the NAS to provide storage capacity.
- Once powered on, the NAS contacts the DHCP server to acquire an IP address.
- Users can access and manage the NAS using this IP address over the network.
- When a user opens a file share on the NAS, they can seamlessly access files as if from a local folder.
- RAID technology provides data redundancy by using multiple drives together.
The main protocols used by NAS for file transfers are:
- SMB/CIFS: Allows Windows, Mac, Linux computers to access files on the NAS. Uses TCP/IP.
- NFS: Used between UNIX and Linux computers and NAS devices. Transfers files more efficiently than SMB.
- AFP: Used for Mac OS X devices to access NAS shares.
- FTP: Transfer files to and from the NAS using the standard FTP protocol.
Benefits of Using NAS
Here are some of the major benefits provided by NAS solutions:
Centralized Storage
Rather than having external drives and servers scattered everywhere, NAS consolidates storage into a centralized location on the network. Users can access this data from anywhere on the network rather than being physically tied to an external drive.
Shared Storage
Files stored on the NAS can be easily shared between many users on the network. This promotes collaboration and ensures data availability to multiple team members.
Backups
Most NAS devices provide inbuilt support for automated backups for protecting data against disasters. The backup destination can be another NAS, external drives or cloud storage.
RAID Support
Redundant Array of Independent Disks (RAID) allows using multiple drives in tandem to protect against data loss. If one drive fails, data can be rebuilt from the remaining drives.
Virtualization Support
Many NAS operating systems allow running virtual machines directly on the NAS. This allows users to enjoy the benefits of technologies like virtualization while still directly accessing their data stored on the NAS.
Economical
NAS devices use commodity hardware, making them an affordable storage solution compared to SAN (Storage Area Networks). They also don’t require modifying the existing network.
Common NAS Uses
Here are some of the most popular uses of NAS in homes and businesses:
Media Streaming
Services like Plex can run directly on many NAS devices to allow streaming media. Users can stream music, photos and videos to devices like smart TVs, gaming consoles etc.
Backups
Both Windows and Mac computers can easily backup files to NAS devices using built-in backup tools. Critical data can be protected this way from hardware failures.
Shared Storage for Home Computers
Rather than copying data between computers using external drives, home NAS allows seamlessly accessing and sharing files between Windows and Mac computers.
Website Hosting
Many NAS operating systems like FreeNAS allow hosting websites using platforms like WordPress or web servers like Apache directly on the device due to their built-in virtualization capabilities.
CCTV Recording
The large storage capacity of NAS devices makes them well-suited for storing surveillance camera recordings from IP cameras.
Development Environment
Programmers working in teams can store project files on the NAS. Virtual machines created on the NAS allow setting up tailored dev environments.
Email Server
Companies can use NAS devices to host their email server and store all associated email data in a central place that can be accessed from anywhere on the network.
Types of NAS Devices
NAS devices are available in a number of different form factors designed for various use cases:
1. Consumer/Prosumer NAS
These are entry-level NAS units meant for home users and smaller businesses on a budget. They use desktop form factors and cheaper hardware components to lower costs while still providing basic NAS functionality.
2. Rackmount NAS
As the name suggests, these NAS devices are designed to be mounted into standard server racks. They provide greater scale-out capabilities for enterprise environments using features like clustering. Most business-class NAS products are rackmounts.
3. Mini/Compact NAS
A mini or compact NAS comes in a smaller desktop form factor, but still packs decent internal storage and compute performance. The smaller size makes them easy to deploy in homes or remote offices.
4. Portable NAS
These portable NAS devices often use laptop hard drives to provide storage capacity. Their compact size and integrated battery makes them easy to carry around and access data on the go.
Leading NAS Operating Systems
While NAS can run any standard computer OS like Windows or Linux, they work best with operating systems customized for the challenges of storage environments. Here are some leading NAS operating systems:
| NAS OS | Description |
|---|---|
| FreeNAS | Free and open source NAS software based on FreeBSD. Includes file sharing, virtualization, backups etc. |
| OpenMediaVault | Linux based open source NAS OS. User-friendly and has plug-ins for added features. |
| Rockstor | Another Linux based open source NAS focused on ease of use, encryption and Kubernetes integration. |
| UNRAID | Proprietary NAS OS with excellent virtualization features and community support. |
| Windows Storage Server | NAS focused OS from Microsoft designed for Windows environments. |
Conclusion
NAS or Network Attached Storage offers centralized file storage accessible to all devices on a network. Compared to general purpose servers, NAS devices are optimized for storage performance, management and sharing capabilities. Leading NAS operating systems like FreeNAS allow even home users to build DIY NAS solutions on commodity hardware that can stream media, run virtual machines and automate backups.