Network Attached Storage, or NAS, is a dedicated device that stores files centrally on a network so multiple users and devices can access them without relying on individual computer hard drives or cloud subscriptions. It sits between a simple external hard drive and a full business server in both cost and capability.
Quick Answer
A NAS is worth buying if you need to share files across multiple devices, want automatic backups for your home or office, or need reliable local storage without paying ongoing cloud subscription fees. A 2-bay NAS suits most home users, while a 4-bay or larger NAS suits small businesses needing more capacity and redundancy.
What Is Network Attached Storage?
A NAS is a small dedicated computer running specialised software, connected directly to your network via Ethernet, that provides shared file storage accessible to any authorised device on that network. Unlike a USB external drive plugged into a single computer, a NAS device is available to every device on the LAN simultaneously, and often remotely as well.
Key Benefits of a NAS
- Centralised file access. Every device on the network can reach the same files without copying data between machines.
- Automatic backup. Most NAS devices support scheduled backups from connected computers, reducing the risk of data loss.
- Data redundancy. Multi-bay NAS devices support RAID configurations, protecting data even if one drive fails.
- Remote access. Many NAS systems allow secure access to your files from outside the network, similar to a private cloud.
- Lower long-term cost. A one-time NAS purchase can work out cheaper than ongoing cloud storage subscriptions for large amounts of data.
How Many Bays Do You Need?
- 1-bay NAS. Basic file storage and backup for a single user, with no redundancy if the drive fails.
- 2-bay NAS. The most common home choice, allowing a mirrored RAID 1 setup so data survives a single drive failure.
- 4-bay NAS. Suits small businesses or serious home users, offering more capacity and flexible RAID configurations for both performance and redundancy.
- 6-bay and larger. Used by businesses needing significant shared storage, often supporting multiple RAID arrays and virtualisation workloads.
Understanding RAID on a NAS
RAID (Redundant Array of Independent Disks) spreads or mirrors data across multiple drives. RAID 1 mirrors data across two drives, so if one fails, the other still holds a complete copy. RAID 5, available on NAS devices with at least three drives, balances capacity and redundancy by allowing one drive to fail without data loss. RAID is not a substitute for a proper backup, since it protects against drive failure, not accidental deletion or ransomware.
NAS vs Cloud Storage
| NAS | Cloud Storage | |
|---|---|---|
| Ongoing cost | One-time hardware purchase | Recurring subscription fee |
| Access speed on local network | Very fast | Limited by internet speed |
| Data control | Full physical control | Managed by third-party provider |
| Setup effort | Requires initial configuration | Minimal, ready to use immediately |
| Best suited for | Large local storage needs, businesses | Simple file sync, small storage needs |
How a NAS Fits Into Your Network
A NAS connects to your existing LAN through a standard Ethernet port, typically via your main network switch. See our network switch buying guide for how to make sure your switch can handle the additional traffic a NAS generates, particularly if using Gigabit or faster connections.
Frequently Asked Questions
Is a NAS worth it for home use?
Yes, if you regularly share files across devices, want automatic backups, or store large media libraries that would be expensive to keep in the cloud long term.
How many drive bays do I need?
A 2-bay NAS suits most home users wanting basic redundancy. A 4-bay or larger NAS suits small businesses or users needing more capacity and flexibility.
Does a NAS replace the need for backups?
No. RAID protects against drive failure but not against accidental deletion, theft, or ransomware, so a separate backup strategy is still recommended.
Can I access my NAS remotely?
Most modern NAS devices support secure remote access through the manufacturer’s app or VPN, letting you reach your files away from home.
Is NAS storage faster than cloud storage?
On your local network, yes. A NAS is typically much faster than cloud storage, since it is not limited by your internet upload and download speeds.
Related Reading
- Network Switch Buying Guide
- LAN Network: Advantages and Disadvantages
- Network Security: A Complete Guide for Businesses
For background on RAID configurations referenced in this guide, see the SNIA storage networking primer.