Everyone agrees backups matter; almost nobody has a working one. The gap is usually not laziness but confusion — is cloud sync enough? (No.) Do I need special software? (Sometimes.) Here is a concrete plan built on the industry-standard 3-2-1 rule, with specific free and paid tools and, crucially, how to prove it works.
The 3-2-1 rule in plain terms
Keep 3 copies of anything you care about, on 2 different types of media, with 1 copy off-site. In practice for a home user that means: the original on your laptop, a second copy on an external drive at home, and a third in the cloud. The logic is that a single failure — a dead drive, a stolen laptop, a house fire, a ransomware hit — can never take out all three at once.
Copy 2: the local backup
An external SSD or drive plus automated software covers the fast, local copy. On Mac, Time Machine is built in, free, and excellent — plug in a drive and it versions everything hourly. On Windows, File History works for documents; for a full disk image, the free Macrium Reflect (free tier) or Veeam Agent are solid. The key word is automated — a manual backup you do “when you remember” is the one that will not exist when you need it.
Copy 3: off-site, versioned cloud
For the off-site copy, use a true backup service rather than plain sync. Backblaze Personal (~$9/month, unlimited) backs up an entire computer continuously and keeps versions, so you can roll back a file to before it was corrupted or encrypted. Its versioning is what makes it a real defence against ransomware, unlike Drive or Dropbox. For the technically inclined, Duplicati or restic (both free) encrypt and push backups to cheap cloud object storage.
The step everyone skips: test the restore
A backup you have never restored is a hope, not a backup. Once a plan is running, actually practise a restore: pick a file, delete it, and bring it back from each copy. Do a bigger test once a year — restore a folder to a different location and confirm it opens. We have seen “backups” that had been silently failing for months; a five-minute restore test would have caught it. Set a recurring reminder and treat the test as part of the backup, not an optional extra.
The 3-2-1 rule, and why each number is there
The most durable backup guidance compresses to three numbers: keep three copies of anything you care about, on two different kinds of media, with one copy held somewhere else entirely.
Each element defends against a distinct failure. Three copies means a single corrupted file does not leave you with nothing, because the odds of simultaneous independent failure are far lower than the odds of one. Two media types protects against a fault that affects one whole class of device, such as a drive model with a manufacturing defect or a controller failure that takes several disks at once. The off-site copy is the one people skip, and it is the one that matters during fire, flood or theft, because those events destroy everything in a single building regardless of how many drives were in it.
Sync is not backup
This distinction causes real data loss. A synchronisation service propagates changes: that is its purpose. Delete a file on your laptop and the deletion is faithfully copied everywhere. Encrypt your files with ransomware and the encrypted versions replace the good ones across every synced device within minutes.
A backup keeps historical versions that are not overwritten by current changes, so you can return to a point before the damage. Many sync services do offer version history and a recycle bin, which softens this considerably, but the retention window is often thirty days or less and it is the first thing worth checking rather than assuming.
A backup you have never restored is a hypothesis
Backups fail silently. Jobs stop running after an update, a drive fills, credentials expire, an excluded folder quietly grows into the important one. None of this announces itself, and the usual moment of discovery is the moment you need the data.
The remedy is to actually restore something on a schedule. Once a quarter, pick a file at random, restore it to a scratch location and open it. This takes a few minutes and tests the entire chain: that the job ran, that the media is readable, that the credentials still work, that the file is intact rather than merely present. A restore test is the only evidence that turns an assumption into a fact.
What to prioritise when you cannot back up everything
Sort by whether the data is replaceable. Photographs, documents you authored, financial records and correspondence are irreplaceable and belong in every copy. Installed applications and operating systems are replaceable by reinstalling, and consume space that is usually better spent on versions of the irreplaceable material. Between those sits configuration, which is technically reproducible but represents hours of work, and is small enough that including it costs almost nothing.
Common questions
What is the 3-2-1 backup rule?
Keep 3 copies of your data, on 2 different media types, with 1 copy off-site. It protects against any single failure taking out all copies at once.
Is Dropbox or Google Drive a real backup?
No — they sync, so deletions and corruption spread everywhere. A real backup keeps versioned copies you can roll back, like Backblaze or Time Machine.
What is the best cloud backup service?
Backblaze Personal (~$9/month, unlimited) for most people, thanks to continuous backup and file versioning that defends against ransomware.
How often should I test my backups?
Do a quick file-restore test regularly and a larger folder restore once a year. An untested backup can fail silently for months.