How to set up a 3-2-1 backup at home

The rule is three copies of your data, on two kinds of storage, with one copy somewhere else. Photographer Peter Krogh is widely credited with the phrasing. At home it works out to the files on your computer, a copy on an external disk, and a copy in the cloud.

A cloud sync folder doesn't count. Deleted files can vanish from it too.

Copy two: a local disk

On a Mac, use Time Machine. Apple's support page says you need a USB or Thunderbolt drive with at least twice your Mac's storage, used only for backups. Steps on macOS Ventura or later:

1. Open System Settings, then General, then Time Machine.
2. Click Add Backup Disk, pick the drive, click Set Up Disk.
3. Turn on Encrypt Backup and set a password.

Apple says you'll need that password to restore. Write it down somewhere that isn't the Mac.

Time Machine keeps hourly backups for 24 hours, daily for a month, weekly after that. When the disk fills it deletes the oldest. Windows users: this guide covers the Mac for the local copy, so use whichever local backup tool you already trust, then carry on below.

Copy three: offsite

Pick one.

Backblaze Computer Backup. The page lists $9 a month, $8.25 a month on a yearly plan and $7.88 on a two-year plan (checked November 1, 2026). Storage is unlimited and connected external drives are included. Files are encrypted before they leave the computer, and an optional private encryption key means only that key opens them. Keeping versions forever is a paid extra whose price the page doesn't list.

Backblaze's page doesn't spell out the number of computers a personal license covers, so confirm it before you buy for several machines.

restic, free. It's a command-line tool and you supply the storage. Its docs are blunt about the password: lose it and the repository is unreadable. The setup, from restic's documentation:

• Create a repository: restic init --repo /path/to/repo
• Back up a folder: restic -r /path/to/repo backup ~/Documents
• Run restic check after the first backup, and regularly after that

For Backblaze B2 storage, the docs recommend the S3-compatible API over the native B2 backend, because the native one has error-handling issues. Make S3 keys in B2, export them as AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY, then run restic -r s3:https://<endpoint>/<bucket> init.

Restic costs nothing, but you'll pay B2 for the space. The Backblaze page has the unlimited-plan numbers and the restic page the licence.

Test a restore

A backup you've never restored is a guess. Pull one file back from each copy. Time Machine and Backblaze both have restore tools. With restic, restic ls lists a snapshot's contents.

Then put a reminder in the calendar for six months out and do it again.

Which offsite option fits? Backblaze against IDrive covers the shared-quota question. Our Backblaze review lists the limits, and Time Machine alternatives covers the Mac-specific options.