Wednesday, 08 July 2020 12:00

On the importance of back-ups

Written by Hans van Bemmelen

Blog BU Data safe

This item is based on the SENSE Tech SIG meeting of 28 May 2020 (moderated by Jenny Zonneveld and me) and describes my approach to back-ups. During the SIG meeting, we also discussed other aspects of IT resilience that I might cover in a future blog post.

Most of us depend on personal computers for work, and store our documents on a hard disk. The computer also uses a hard disk to store its operating system and applications. Any hard disk will fail: either soon after you buy the computer or a decade later, suddenly or after some warnings – but fail it will. For the purposes of this discussion, there is no difference between traditional hard disks (with a spinning disc covered with a magnetic recording medium) and solid-state disks (SSD, fully electronic, without moving parts).

The threats to your data include failure or theft of your PC or hard disk, viruses/ransomware, fire and flooding. You have to assess what threats are relevant to your situation and then define a back-up strategy.

External hard disks

I use computers with two hard disks: an internal one (for the operating system and applications) and an external one for data (, my work and accounts). The advantage is that if my computer fails, I can disconnect the external hard disk and take the computer in for repair without having to worry about the shop gaining access to confidential data. At the same time, I can connect that external disk to my laptop and continue working.

Back-up options

Back-ups can be created in several ways:

  • Automatically, in the background (eg, Apple Time Machine)
  • Initiated by the user, through dedicated software (eg, SyncBackPro)
  • By the user, through manually copying the relevant directories

I have considered options 1 and 2, but decided that they would make me too dependent on dedicated software when restoring the back-up and put me at risk of that software not being available when I need it. Therefore, I’ve gone for option 3 – also to prove my Luddite credentials...!

Back-ups can be written to:

  • Another hard disk (either permanently connected to your PC, or only connected when required) or a USB stick
  • The Cloud
  • An optical disk (eg, DVD)

Option 1 is obviously convenient and protects against the failure of the main hard disk. However, if my computer got infected by ransomware this might encrypt both my main hard disk and my back-up disk, rendering both useless. Option 2 means relying on an external service provider, which does not appeal to me. There are also issues concerning reliability, time required for a restore, and confidentiality. So I decided that option 3 – writing the back-up to a DVD-DL disk – was the safest option. It has a capacity of around 8 GB which is enough for my work in progress, e-mail and accounts, etc.

Back-ups can be stored:

  • In your office
  • In a data safe
  • Off-site

Option 1 is the most convenient, but if there is a break-in or fire, you might lose both your primary hard disk and your back-up. Option 3 is the most secure, but not always convenient. I use option 2, and have invested in a fairly secure and fireproof data safe. They're quite expensive – the fireproof model pictured above will set you back about €1,500 – but it will last me a lifetime. Additionally, every now and then I take a back-up off-site (which obviously raises data security issues).

Further musings:

  • It is essential to regularly test whether you can restore your back-ups, both to your main computer and to another computer. If you have to get a new computer to recover from a major failure, you must be able to install any back-up software you use on it. It might therefore be an idea to store a copy of the software together with your back-ups.
  • You have to decide on a back-up frequency. I've opted for weekly back-ups on DVDs stored in the data safe. During the week, I copy the key files I am working on to a USB stick.
  • Encrypting the back-up improves data security, but means you will need the relevant software to decrypt it for a restore. My normal (securely stored) back-ups are not encrypted, but my off-site ones are.

A further aside: a decade or two ago, I was writing a similar article for the then-SENSE newsletter. I'd almost finished it when I lost the file and noticed a burning smell coming from the external hard disk, which had failed disastrously. A salutary reminder of the transitory nature of computer data. So, fingers crossed this time...

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