6 questions to ask before buying cloud storage
Buying the wrong cloud storage ser vice could be costly in both how much it costs and the time it takes to unpick the mess
1 How much storage do you need?
Let’s reframe the question: what do you actually need to back up? This may be a lot less than you imagine: even if your hard disk is nearly full, a lot of that space will be taken up by Windows and program files, not to mention miscellaneous downloads and temporary files that don’t need to be archived for the ages. Carry out an audit of what really needs protecting and you may find it’s just a gigabyte of documents and spreadsheets.
It’s worth thinking about whether you want to include music files and photos in this audit, since these are likely to take up the lion’s share of your personal storage. If your songs were bought from iTunes or a similar service, you can normally redownload them for free in the event of a crash. Alternatively, you can use free cloud services such as Google Play Music and Google Photos to store backup copies of your songs and pictures. That said, always read the small print: uploaded files may be compressed or transcoded, so they won’t retain the full quality of the originals.
And don’t be too discriminatory about what gets backed up. It’s easy to think of backup services primarily as protection against system failures, but they can also provide a safety net when you delete a file that seems unimportant at the time, then later
“In all, we’d recommend an inclusionist approach: if there’s any doubt as to whether an item should be backed up, play it safe”
realise you need it after all. But for that to work, you need to start by backing up all the files that don’t, at the time, seem useful.
In all, we’d recommend an inclusionist approach. If there’s any doubt in your mind as to whether an item should be backed up, play it safe and include it in your audit. Then, pick a cloud backup option with plenty of room for this, plus all the updates and new files you’re going to make in the foreseeable future. Since this may well be hard to estimate, you might be tempted to go for an unlimited-storage option – although you can save money by picking a service with a fixed quota.
2 What devices should you protect?
In this month’s Labs, we’re focusing on personal backup services, which are mostly aimed at single users. That often means you pay a monthly or annual fee to back up files from a single PC or Mac. Under a licence like this, if you want to back up a second system, you’ll normally need to pay for a second subscription.
If you want to protect a whole household full of computers, it’s a good idea to look instead for a service that covers them all under one subscription. These services typically come with fixed storage limits, because if they were to offer unlimited uploads from five or ten PCs, the sheer quantity of data would be cost-prohibitive to store.
What if you want to back up the contents of an external drive? As our feature table overleaf shows, some providers will count a USB hard disk as just another drive and back it up under a single-PC licence; others see this as an additional service. Similarly, if you want to back up a NAS drive, you may well find your regular service doesn’t cover it, which is fair enough if you’re talking about multiple terabytes of data, but a bit annoying if it’s just a few folders.
Most cloud backup services also offer dedicated smartphone apps for Android and iOS. Some of these only let you browse and download files that have been uploaded from the desktop, but others let you back up downloads, photos and other items from your phone.
3 How many file versions?
Backup isn’t just about recovering files that have been deleted. On occasion, you may need to turn back the clock and access an older version of a file, before it was edited and all the useful information about x was replaced with more up-to-date information about y.
Most cloud backup services will automatically detect when a file has been updated, and will keep a copy of the old version alongside the new one. Exactly how this is handled varies
from service to service: some offer a time-limited rollback period, while others retain a set number of versions. For example, Acronis True Image 2017 automatically stores the most recent 20 versions of a file, ready to be recovered with a click.
Very few services will store unlimited file versions, though – so if you want to be sure of not losing potentially useful data, it’s a good idea to get out of the habit of repeatedly updating and overwriting old files. It’s far safer to rename them in some self-explanatory way (for example, add “2016 version” to the end of the filename), then copy their contents into a new file and work from that.
4 Continuous or scheduled backup?
Traditionally, it’s been considered good practice to run backups to a fixed schedule: a business, for example, might typically run a big central backup job in the middle of the night, when no-one’s around to be impacted by the increase in network activity and server load.
For personal cloud backup, however, continuous backup is the norm: in other words, when you edit or save a file, you can expect it to be backed up right away, or at worst within an hour. This makes a lot of sense as the most common file types are pretty small and can normally be sent up the line in a matter of seconds, meaning you get very good protection with little or no impact on your computing experience.
However, there may be situations in which continuous backup isn’t appropriate. For example, you might be working with very large files, and not want to tie up your connection with constant uploads. Or, you might be making lots of little edits all day that you don’t want to count towards your versioning limit.
In this case, a nightly or weekly backup run might make sense – or you might even prefer your software to launch a backup only when manually triggered. As you’ll see from our feature table overleaf, most systems let you control scheduling, but some are more flexible than others.
“Hybrid backup ensures that you’ll be able to get at your backed-up files, even if your internet connection goes down”
5 Do you need hybrid backup?
As we detail to the right, one of our tests this month involved timing how long it took to restore files from each of the cloud backup services. Most providers let us download our files at close to the full speed of our internet connection. But if your line is slow, you could still be left waiting around for hours to recover critical files.
If you’re concerned about long restoration times, the answer could be hybrid backup. That sounds like enterprise jargon, but it simply means simultaneously backing up to both the cloud and a local destination such as an external hard disk or NAS appliance. This means that when you need to recover files from your archive, you can get them from a local source rather than having to download them over the internet. If you need to restore multiple gigabytes of data, the speed advantage can be huge.
There’s another benefit to hybrid backup too: it ensures that you’ll be able to get at your backed-up files, even if your internet connection goes down or your cloud provider goes out of business. Certain cloud backup services include hybrid backup features. However, if yours doesn’t, there’s nothing stopping you from installing a basic free backup tool and setting it to make local backups in parallel with your chosen cloud client.
6 What about data security and encryption?
Many cloud backup services are based in the US, so unsurprisingly that’s where your data gets stored. In all cases it’s encrypted at rest, so you don’t need to worry too much about an opportunist hacker getting into the system and rifling through your personal emails and so on.
Note, however, that by default the encryption key is held by the backup operator. They could be legally compelled by the powers that be to decrypt your data and hand it over. Or, in the case of a major security breach, a dedicated hacker could theoretically even get their hands on the key and thus unlock your private information.
These scenarios seem very unlikely, but if you’re wary of the US authorities, you may feel happier choosing a provider whose servers are in a different locale. For absolute peace of mind, several services also let you specify a custom encryption key which is never seen by the operator (the encryption and decryption are handled locally on your PC). This makes it effectively impossible for your data to leak from the data centre – but it puts a big responsibility on you to take care of the key, because no-one in the world can get your files back if it’s lost.