GROUP TEST: NAS drives
Benny Har-Even reveals what to look for in a NAS drive and reveals our top picks
NAS stands for Network Attached Storage and it enables you to have a large amount of storage connected directly to the router, making it available to all your devices. NAS drives are designed to be left on permanently, which means you can access your music, movies, photos and documents without having to make sure a computer is turned on.
One of their most popular uses is for media playback, so files can be viewed on your TV, without having to connect a PC. A NAS drive also uses much less power than a regular computer making them much cheaper to run. For ease of setup and use, a dedicated NAS drive is hard to beat.
It’s vital that you opt for a drive that has enough storage to meet your needs both now and in the future. Plenty of NAS drives come with no disks – these are known as diskless or bare drives. Their advantage is that you can choose the drives you want and how much capacity you need.
You can now get disks up to 10TB in size, though for each disk you’ll be paying at least £400 or so for the privilege. 4TB disks are arguably the sweet spot, at around £120.
Disks for NAS drives
When you choose your disks, look for ones that have been designed to work specifically with NAS boxes. NAS-optimised features include more secure construction providing more resistance to vibration, which makes a lot of sense for a drive that’s designed to be on the whole time. They also offer power management, so they can adjust performance based on their temperature. These drives also offer special features in firmware known by WD as TLER (Time-Limited Error Recovery) and by Samsung and Hitachi as command completion time limit (CCTL). This optimises the error correction for drives when they are installed in a RAID array (explained below) as is usually the case with NAS drives.
RAID, stands for redundant array of inexpensive disks. It can be complex, but at a basic level you’ll want to use it primarily to provide redundancy, so if a disk fails your
You can now get disks up to 10TB in size, though for each disk you’ll be paying at least £400 or so for the privilege. 4TB disks are arguably the current sweet spot, at around £120
data is still safe. There are many variants, but three of the most popular are known as RAID 1, RAID 5, and RAID 6.
Most NAS drives offer at least two bays, which means you can set them up as
RAID 1. In this scenario, the second drive is a mirror of the first, so if one drive fails completely all your data is safe on the other. You then can replace the faulty disk and rebuild the RAID array, though this will take several hours.
RAID 5 requires at least three drives and offers parity data. That means a RAID 5 array can withstand a single drive failure without losing data or access to it. As data is ‘striped’ across three drives, reads are fast, but at the expense of slower writes because of having to also write the parity data.
RAID 6 requires four drives but offers both striped and dual parity, so two drives could fail and the RAID could still recover.
Whichever you choose don’t consider RAID to be your only backup. First, you’re relying on the RAID array rebuilding successfully, and while from experience we know that it does work, it is another point of failure. If the box just dies, you’ll still lose all your data. To mitigate this you’ll want another external backup, preferably to the cloud. Most NAS offer native applications for certain providers, but these will require subscription to the service and won’t necessarily be from your preferred one.
Another feature to look out for is hot-swap capability, which enables you to take out or add a drive without having to power down first, which could be important if you’re running business applications off your NAS and want to maintain uptime when replacing or adding a drive.
You should also consider whether you’ll need remote access to the drive. Previously this required signing up to a third-party DNS service, but these days you can just sign up for an account with your NAS manufacturer as you set up the drive.
Login to the account and they’ll handle the connectivity to your box at home. If privacy is a concern you many not wish to go down this route, but for ease of use it’s the way to go.
It’s also worth considering how powerful you need your NAS’s processor to be. The dedicated OS that NAS drives use are lightweight, but a faster processor and more memory will enable features such as transcoding. This means any media files will be converted on the fly into a playable format, so you don’t have to rely on your client device being able to play them smoothly. For example, HEVC H.265 files are becoming popular due to the small file sizes, but devices that can play them back natively are still uncommon. Transcoding will deal with this for you if your NAS is powerful enough. If, however, you have 4K files and want to play these you’ll need a fast NAS.
Finally, you might want to consider to what use you’ll be putting your NAS to. As well as media a small business owner will want to know what applications it has to offer, such as setting it up as an email server, a VPN server or using it to host a website.