A 3-2-1 backup plan you can use at home

Map the three copies

The Canadian Centre for Cyber Security describes 3-2-1 as three copies of your information, using two media types, with one copy off site. Count the working original as the first copy. Identify two additional destinations with recoverable backups of the files you want to protect.

For a home example, originals could live on the laptop’s SSD, a versioned backup could go to an external hard drive, and another backup could go to a suitable remote service. That is a layout to evaluate, not a recommendation for a particular provider. Check what each destination contains before counting it.

Give each destination a job

Use the local copy for everyday mishaps: an overwritten spreadsheet, a missing folder or a computer that will not start. It can also reduce how much you need to download when rebuilding a large collection. Keep the destination connected often enough to contain recent work.

The remote copy should remain available if the computer and local backup disappear together. Think about where your equipment spends the night. A second drive permanently stored in the same laptop bag offers little help if that bag is stolen. Choose another location or service with a recovery process you understand.

Check what happens when you delete something

A file appearing on two devices does not necessarily mean two independent recovery options. Synchronisation can repeat a deletion or an unwanted edit. Microsoft’s OneDrive documentation, for example, explains that deleting an online-only file deletes it from OneDrive online and on other devices too.

Before counting a synced folder in the plan, check its version history, deleted-file recovery and account requirements. These features may be useful, but the question is specific: can you recover the document as it existed before the mistake? A mirror of the current mistake is not the recovery you need.

Think through a few ordinary failures

If the laptop is stolen, what would you use? If the external drive is dropped, where is the other backup? If an online account is temporarily unavailable, do you still have recent local files? Answering these questions often exposes a shared dependency that the copy count misses.

An offline destination can reduce exposure to unwanted changes from a compromised computer. It only helps if it receives useful updates, then is safely disconnected when appropriate. Choose a routine you can maintain. A simple rotation that happens is more useful than an elaborate arrangement that is forgotten.

Run a small restore rehearsal

Make a test folder with a text document, photograph and project file you can inspect. Let the backup finish, then restore that folder to a new location. Open the restored files. A filename in a backup browser tells you less than confirming that its contents are usable.

Try another recovery date if your software keeps history. Keep recovery instructions somewhere you can reach without the original laptop. Protect passwords and recovery codes rather than leaving an unencrypted list beside the drive.

• Record which files each backup includes.
• Record the last successful date, not only the scheduled date.
• Restore into a separate folder for the rehearsal.
• Keep the originals until you have checked the restored versions.

Make maintenance small enough to repeat

For a household with 250 GB of personal files, a useful first session can be modest: identify key folders, create a local backup, decide where the remote copy will live, and restore a sample. Improve the schedule and capacity as you learn what changes.

Review the arrangement after a month and after major device changes. Check whether new project folders were included, whether credentials remain recoverable, and whether free space is shrinking too quickly. Aim for a routine you understand instead of a collection of green checkmarks you have never tested.