I use a 1TB USB hard drive – it’s connected to my wifi router – as the main storage for my home laptop and mobile. I don’t have a secondary backup and have read that NAS drives are a better option for this. Would this be OK as backup storage? I also have some documents/pictures on OneDrive. Adele
The most important thing to remember about hard drives is that they fail. In fact, the seven-year-old 2TB USB drive I was using to backup my desktop PC failed on Saturday. That wasn’t a problem because my PC’s hard drive was still fine and I had my 2TB backup backed up to an 8TB USB drive. (The 8TB drive also backs up the backups to two laptops.) On Monday, I replaced the dead drive with a new 4TB USB 3.0 drive, because you can never have too much backup space, and it’s really not worth buying anything smaller.
This sounds like the sort of setup that would suit you, too.
A couple of 4TB drives would currently set you back around £174, though you could save about £33 by buying 2TB drives, or about £25 by buying 3TB drives. (I’m using Seagate Expansion external hard drives to simplify the example.)
You could buy a two-bay NAS (network attached storage) device, but it would be roughly twice the price. First there’s the cost of a good, cheap NAS, such as a Synology DS218j (£165.23). Then there’s the cost of two hard drives to fill it. A couple of 4TB Seagate Ironwolfs (£190) or fast and ultra-reliable HGST Deskstars (£229), perhaps? Total cost: between £350 and £400.
NAS drives have their uses, but they are not the cheapest way to back up a laptop.
Before you buy anything, work out what you are trying to achieve, and why. In particular, distinguish between backups and archival storage.
The original point of having a backup was to get your PC up and running again if a hard drive failed. This resulted in compressed, incremental backups. It was a good solution for people who had one desktop PC that stored all their data.
That scenario changed when people bought laptops instead of, or as well as, desktops. It changed even more with the arrival of 2-in-1s with tiny 32GB or 64GB storage chips. Now you had loads of files – music, movies, multi-megabyte photos – that didn’t even fit on your PC. Further, you probably had personal photos and records – banking information, work and health records – that you didn’t want to carry around on a laptop that could easily be lost or stolen. In other words, you needed archival storage as well as a backup.
It’s important to remember that backup systems, including Apple’s Time Machine, do not provide archival storage. If you delete things to make room on your hard drive, they will eventually disappear from your backup drive, as old backups are deleted to make room for new ones.
You must also consider other threats to your irreplaceable data. The main ones are theft, disasters (fire, flood, earthquakes, asteroid strikes etc) and malware attacks.
To guard against these, you need a backup that you won’t lose along with your PC or laptop, which usually means “off-site storage”. The options include leaving a USB hard drive with a friend or relative, or at work, or stowing the data online somewhere.
There’s also the threat of ransomware, which encrypts your files and tries to blackmail you into paying to get them back. Today’s ransomware will also encrypt the files on connected and networked drives, which is why you need to back up your backup drives. The alternatives include optical discs – CD, DVD or Blu-ray – and storage devices that are kept separate from your PC, such as USB thumbdrives and SD cards. These are not the best options for archival storage, but they are a cheap way of keeping extra copies of irreplaceable files.
Some ransomware can affect OneDrive files, but you may be able to restore good versions from OneDrive’s recycle bin. See Microsoft’s Ransomware FAQ and Restore deleted files or folders in OneDrive.
Backing up to external hard drives
An external hard drive (EHD) is simplest and fastest way to back up a PC running Microsoft Windows.
First, format the EHD to use Windows’ NTFS file system, if necessary, then create a folder to store an archive of your personal files. You can drag and drop them across, or copy and paste them in. You will be able to read these files from any Windows PC, which is vital if you no longer have access to your laptop for some reason.
Next, set up an old-style incremental backup. You can do this with Backup and Restore (Windows 7), which is in the Control Panel in Windows 10, or use one of the many free – often superior – alternatives. (Warning: by default, the Windows 7 software only backs up a few important folders, not the whole drive.)
You can also, optionally, make a “drive image” or snapshot of your PC’s hard drive at that particular time. (See Back up and restore your PC.) Restoring a drive image is the fastest way to get back to work after a hard drive failure. It’s also a good idea to make a recovery DVD or (blank 8GB) flash drive to help fix problems if your PC has a problem starting.
Finally, copy your whole backup drive to another EHD. For preference, this one should be a different make or model: you don’t want two drives failing to the same bug at the same time.
You can update your archive using Microsoft’s SyncToy or similar free software. I use open source FreeFileSync because it’s better than the alternatives, has good tutorials, and is still in active development. It makes it easy to see which files will be changed, which helps avoid accidental errors. It can also sync files to network shares, cloud storage (using FTP and SFTP) and mobile devices (using MTP). You can save complicated backups as batch files so it only takes a few seconds to repeat them, and you can run several batch files at the same time.
Each backup drive mirrors the previous one, so if you accidentally delete a file or folder on your laptop then your sync program will delete it on the backups as well. The alternative is to use the update mode, which SyncToy calls Contribute. This backs up new files without deleting files you may have deleted, moved or renamed.
You can back up your backup every day or every week or whatever: it depends how many new files you add and how important they are. The key point is that this second EHD is not attached all the time, or at least is turned off when you’re not actually using it.
Do you need a NAS?
There are lots of good reasons to buy a NAS. The main ones are to share and stream data from multiple PCs, tablets, smartphones, smart TV sets and other devices. But if you don’t need these features, why pay for them?
A NAS is actually a low-end computer with its own processor, memory and operating system – usually a minimal version of Linux. In fact, you can convert an old PC into a NAS by running software such as Amahi, FreeNAS (recommended) or Open Media Vault.
For more information, see my earlier answer, Which NAS should I buy to store files?
A good NAS should also be able to run a wide range of apps: Synology has about 125 and QNAP almost 200. Popular apps include the Plex Media Server (for streaming), Surveillance Station (to manage home security cameras), and Download Station (to download files from the net). This is where cheap NAS devices tend to fall short.
But a NAS isn’t an ideal backup device. Using RAID 1, a NAS can mirror two hard drives in one box, but you can still fall victim to the mirroring problem. And if it’s stolen or blows up you have lost both backups at once. The real function of RAID isn’t to provide a backup, it’s to ensure data is always available from an always-on server. It’s about availability, not security.
If you buy a NAS, you should still back it up to an EHD or cloud service.
Have you got a question? Email it to Ask.Jack@theguardian.com