How to choose the right network attached storage drive (Nas)

This is the second of two articles on choosing high capacity storage products. Here we look at network attached storage drives. You can also read our guide to choosing a USB external hard drive.

Using a USB2 or USB3 disk to store files used by more than one computer means you have to disconnect it from one and plug it into the other. As many people have a home network, there is an easier way to achieve the same result.

Network-attached storage (commonly called Nas) devices are basically hard disks with Ethernet built in. Once set up on the network any computer with home network access can save or retrieve files to the Nas.

That means a Nas device is in effect a home server, and most models can also share printers, store video and music for use on network-ready TVs, and even be accessed remotely over the internet.

Read more: How to choose the right USB external hard disk | Cloud storage advice

Nas with disks, Raid and Wifi?
There are three key points to consider when buying a Nas.
•    First, Nas devices are available in ‘populated’ and ‘bare’ forms – put more simply, with or without hard disks.
•    Secondly, you can get Nas products with or without Wifi – those without need to be plugged into the router or into a compatible extender, such as a powerline adapter.
•    And thirdly, Nas devices with more than one disk can make use of a technology called Raid (short for Redundant Array of Independent Disks) that can provide even safer backups and give better performance.

Wifi Nas drives are still more expensive and data transfer speeds will be slower. The Synology Diskstation DS213Air 2-Bay Nas Server costs about £230 without disks, although it can fit up to 8TB of storage space. 

Meanwhile, the Western Digital My Book Live Network Hard Drive provides 3TB of space at £150 but without Wifi.

Bare Nas devices are a great way to put old hard disks to use. Devices with two or more drive bays can start with one hard disk and more can be added, while populated Nas devices are usually sold as sealed units and lack easy-access drive bays for upgrades.

Both offer the same features but some models are easier to use.
Seagate’s 3TB Free Agent Go Flex is a sealed device that costs around £100 and offers a powerful but easy-to-use set of network and internet file-sharing features.

There are even remote-access and media-streaming apps for Android and Apple iOS devices. Alternatively, Synology has a range of bare Nas devices and a good starter option is the Disk Station DS212j for around £160, without drives.

Those Synology’s models also support Raid. Though there are various different ways to set up Raid devices, it is essentially a way of storing data across all available disks rather than on any particular one. This has two important advantages. First, Raid uses some clever disk-management techniques that make Nas devices more resistant to hard disk failure.

If one drive in a Nas with Raid stops working, no data is lost and the disk can be replaced seamlessly (usually without even shutting down the Nas device) – unlike data spread across two or more disk with Windows’ volume-spanning feature.

Second, Nas devices offer vastly more storage capacity than any other option, albeit at a price. A device such as Qnap’s TS-412, fitted with four 3TB drives, costs around £758 from Amazon but the 12TB capacity this provides – enough to hold more than 2,500 full-quality DVD movies – simply can’t be created any other way. That said, lower-capacity devices are available – see our recent Nas reviews for our recent reviews.