The 3-2-1 Backup Rule for People Who Live in the Cloud
· 3 min read · Updated
Keep 3 copies of anything you care about, on 2 different kinds of media, with 1 copy off-site. It is an old rule from the server world, and it still holds. If you live in the cloud, "it is in Google Photos" or "it is in Dropbox" counts as one copy, not three.
A cloud account feels safe because the company runs the servers. It is still one copy in one place, tied to one account that can be locked, billed, closed or forgotten, which is the single point of failure 3-2-1 exists to remove.
Accounts get locked, subscriptions lapse, and providers change their terms or shut a service down. Sync can also faithfully copy a deletion or a corruption to every device before you notice. In each of those cases, everything in one cloud means one copy.
A workable 3-2-1 for a normal cloud library needs no server rack:
- Copy 1: the cloud you already use. Google Photos, Drive, Dropbox, iCloud, GoPro Cloud, or whatever holds the originals today.
- Copy 2: storage you own. A NAS or an external drive. It is a different kind of media, under your own roof, and you can still reach it if an account is locked.
- Copy 3: a second, off-site cloud. Object storage like Backblaze B2, Wasabi or Cloudflare R2, or a second consumer cloud. This is the off-site copy that survives a fire, a theft or a drive failure at home.
A backup made once and never updated slowly stops matching what you have. Refresh the owned copy and the off-site copy as often as the originals change: monthly for a photo library, after each shoot for a working archive.
Blober moves data between these copies. It connects to a broad set of cloud providers plus local storage, and it streams files between them through your computer without staging a full copy on your disk. There is no scheduler, so each refresh starts when you run the saved workflow again. With the default deduplication setting, Skip if a file with the same name exists, a re-run skips every file whose destination path is already taken and copies the rest. It compares paths, not contents, so an edited file that kept its name is skipped unless you choose Overwrite the existing file. An interrupted copy resumes where it stopped, so a refresh never turns into an afternoon of restarting from scratch.
Before you trust any of this, open a few files from the owned copy and from the off-site copy. Until you have opened files from a copy, you don't know it works.
What is the 3-2-1 backup rule? Keep 3 copies of your data, on 2 different types of media, with 1 copy stored off-site. It protects you from any single failure, whether a drive, an account or a location.
Does cloud storage count as a backup? A single cloud account is one copy, not a backup. It becomes part of one once you add a second copy on owned storage and a third copy off-site.
What is the easiest second copy for a cloud library? A NAS or an external drive. It is a different kind of media than the cloud and stays reachable even if an account is locked.
How do I keep my backup copies up to date? Re-run the copy whenever the originals change, for example monthly for a photo library. You start each run yourself, because Blober has no scheduler. A re-run with the default deduplication setting skips files that are already at the destination, and an interrupted run resumes where it stopped.