Back up a Mac to Cloudflare R2 or Backblaze B2
An offsite copy protects against burglary, fire and water damage. S3-compatible storage like Cloudflare R2 or Backblaze B2 is affordable for this if you get three things right.
1. A bucket of its own
Create a bucket only for the backup at your provider, for example my-mac-backup. In Cloudflare it is under R2, at Backblaze under Buckets. Keep the bucket private.
2. A key with few rights
Create an API key that can read and write only this bucket, not your whole account. At R2 that is an R2 API token with object read and write for the bucket; at B2 an “application key” limited to one bucket. You get a key ID and a secret key. Keep both somewhere safe.
3. Encrypt on your Mac
Your provider should not be able to read your files, so encrypt on the Mac before anything is uploaded. restic always does: every backup is encrypted with AES-256, the key comes from your password. In Terminal:
export AWS_ACCESS_KEY_ID="…" AWS_SECRET_ACCESS_KEY="…"
restic -r "s3:https://<account>.r2.cloudflarestorage.com/my-mac-backup" init
restic -r "s3:https://<account>.r2.cloudflarestorage.com/my-mac-backup" backup ~For B2 the address is s3:https://s3.<region>.backblazeb2.com/my-mac-backup; the region is shown with the bucket.
What does it cost?
Both providers charge per gigabyte stored per month, R2 without fees for downloading. Current prices are on the provider's pricing page. Size matters most: a home folder without caches and Trash is often much smaller than the used disk. After the first run restic stores only changes, so the backup grows slowly.
The first upload
Depending on your connection the first backup takes hours to days. Keep the Mac on power and don't worry about interruptions: restic continues where it stopped on the next run.
Lifeboat backs up your Mac with restic to a disk, a NAS or your cloud storage, and restores random files every week to show you the backup works. 14 days of everything free, then 1 disk free or Pro for €39 once.
See Lifeboat