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Home Backup Guide: Cloud, External Drives and the 3-2-1 Rule

April 8, 2017
Computer and technology concept

Many people only think about backup after something has gone wrong: a laptop that won’t start, a phone left on a train, or a folder of photos deleted by mistake. A good home backup doesn’t need to be complicated or expensive. It needs to be automatic, it needs more than one copy, and you need to know that you can actually get your files back from it.

This guide covers the main options for home and personal use: cloud backup, external drives and NAS boxes, and how to combine them.

The 3-2-1 rule

A widely used rule of thumb is 3-2-1:

  • 3 copies of anything that matters: the original plus two backups.
  • 2 different types of storage, for example your computer’s internal drive and an external drive, or an external drive and a cloud service.
  • 1 copy off-site, so a fire, flood, burglary or ransomware infection at home can’t take every copy at once.

For most households, that means one local backup (an external drive or NAS) plus one cloud backup. Neither is enough on its own; together they cover each other’s weak spots.

Cloud backup is not the same as cloud sync

This is a very common misunderstanding. Services such as iCloud Drive, OneDrive, Google Drive and Dropbox are mainly sync services. They keep the same files up to date across your devices, which is very useful, but sync copies mistakes as faithfully as it copies good work:

  • Delete a folder on your laptop and it is deleted everywhere.
  • Overwrite a document and the old version is replaced everywhere.
  • If ransomware encrypts your files, the encrypted versions can sync to the cloud too.

Some sync services keep a recycle bin or older versions for a limited time, which can help, but they are not designed as a full backup. A proper cloud backup service copies your files on a schedule, keeps previous versions and keeps deleted files, so you can go back to how things were before the problem started. Turn on any security options it offers, including 2-step verification on the account, as the NCSC recommends.

External drives and NAS

A local backup to an external drive is fast, cheap to run and quick to restore from. Use proper backup software (Time Machine on a Mac, or a backup tool on Windows) rather than dragging files across by hand, and set it to run automatically.

The weaknesses are that the drive sits in the same building as your computer, and if it is permanently plugged in, ransomware or an accidental mass deletion can reach it. The NCSC advises disconnecting removable backup drives when you are not using them and protecting them with a password. External drives also fail like any other drive, especially portable ones that get carried around and dropped.

A NAS (network attached storage) is a small always-on box with its own drives that the whole household can back up to. It is convenient, but it is still a local copy: it is on your network, in your home, and needs its own off-site backup. If a NAS does fail, see our NAS data recovery page.

RAID is not a backup

Many NAS units use RAID, where data is spread or mirrored across several drives so the box can survive one drive failing. That protects against a single hardware fault. It does nothing against deletion, overwriting, corruption, ransomware, theft or the NAS itself failing, because every change is applied to all drives at once. Treat RAID as a way to keep running, not as a second copy. Our RAID recovery page explains what happens when arrays fail.

Versioning: being able to go back in time

Good backups keep several versions of each file, not just the latest one. That is what lets you recover from a mistake you only notice a week later, or from ransomware that quietly encrypted files before you spotted it. Check that both your local and cloud backups keep version history, and how far back it goes.

A simple setup that works

  1. Decide what matters: photos, documents, email, anything you couldn’t replace. The NCSC’s advice is simply to back up anything you value.
  2. Set up an automatic backup to an external drive or NAS, with versioning turned on.
  3. Add an automatic cloud backup service as your off-site copy.
  4. Disconnect removable backup drives when not in use and password-protect them.
  5. Every few months, restore a few files to check the backups really work.
  6. Remember phones and tablets: make sure their cloud backup is switched on.

For a step-by-step walkthrough, see how to back up your data.

If the worst happens before your backup is in place

If a drive fails and there is no usable backup, stop using it. Don’t keep restarting it, run repair tools on it or try the freezer trick. Each attempt can make a recovery harder. Our guide to getting data off a failing hard drive explains what to do.

Data Retrieval Ltd offers a free initial assessment and a fixed, no-obligation quote before any recovery work starts. Call us on 020 7064 4996 or book a case online.

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