backdown

BackDown documentation

How to install BackDown, how it works, step-by-step guides, and every command.

BackDown indexes your drives, finds what's duplicated across all of them, and tells you, with a SHA-256 hash behind every claim, which drives are safe to wipe. It recognises what things are and where they came from, files old drives into one archive, keeps mirrors, watches your drives' health, and gets files back from failing or emptied drives. It runs on your own computer and only ever reads the drives it looks at, except when you ask it to copy into an archive, keep a mirror, or free up a drive.

New here? Start with Getting started: install it, open it, index two drives, see what's duplicated, and ask whether a drive is safe to wipe. Concepts explains the ideas the rest of the docs rely on.

Note

These docs describe BackDown 1.0.0-beta.5: the desktop app, its background service and the backdown command, on Linux, macOS and Windows. It's a beta, so some things will change before 1.0; the status page has what's released and what's next.

Start here

  • Getting startedInstall BackDown, open it, index your drives, see what's duplicated, and find out whether a drive is safe to wipe, in the app or in a terminal.
  • ConceptsDrives and scans, fast rescans, the time slider, hashes and proof, what "safe to wipe" means, copies across file systems, recognised things and where they came from, the background service, and drive health.

Guides

  • Free up a driveDelete only what has a verified copy elsewhere, move what exists only on the drive first, and see exactly what will happen before anything does.
  • File your old drives into one archiveLet BackDown propose where everything on your old drives goes in one archive, and why, then copy it there with every file verified. Nothing is deleted.
  • Merge mailboxesTurn copies of the same mailbox taken at different times into one Maildir, every message once and in the right folder, and export a folder as mbox. The copies are only read.
  • Keep a mirrorKeep a folder, usually part of your archive, copied on another drive, with changed files' old copies kept aside and a sample re-read now and then.
  • Several machinesLet copies on a NAS or another computer count, reached over ssh with your own keys: add a machine, sync it, browse it, gather its drive-health warnings here, and free up drives here against copies there.
  • The swarm and the poolEvery machine you run BackDown on as one: see each machine's drives and free space, find a file wherever it is, declare pool folders on any of them, and pour an old drive into the pool from any machine, each file copied once and verified, then free the drive.
  • Drive healthWhat each drive says about itself, what BackDown can read of it on Linux, macOS and Windows, the warnings and trends it keeps, notifications, other machines' drives gathered here, and what to do when a drive is failing.
  • Rescue a failing driveCopy a failing drive or memory card safely, find deleted photos and documents by their contents, and look for lost partitions and the files on them. BackDown only reads the drive.
  • Recover deleted filesOpen a drive's or card's file system directly, see deleted files with their names and how likely each is intact, and copy them out to another drive, checked. FAT, exFAT and NTFS; ext4 by content instead.
  • Browse without restoringOpen any file on any indexed drive as it was at any scan, read mailboxes as conversations, see SQL dumps as schemas, look inside disk images, and search every drive at once.
  • Chain of custodyEvery copy, move, deletion, link and merge BackDown makes, in a hash-chained log sealed with this computer's key. Export it for evidence handling, and let anyone verify it, with BackDown or without.
  • People, databases, and searching inside thingsSee everyone and every database your drives hold, gathered across drives from mail stores, Nextcloud data, home folders, site configs and dumps; then search inside mail and databases, reusing the indexes already there.
  • Settings, updates and licencesThe Settings view, how often drives are rescanned, updates, notifications, running BackDown for the whole machine, and what's free and what's Pro.
  • Air-gapped machinesBackDown on a computer with no network: a checklist, licences checked offline, and updates carried over on a drive, their signature checked before they're installed.
  • Signed manifests and attestationsSign a statement of exactly what a drive held at a scan that anyone can check wasn't changed, have the service sign one after each scan or on a schedule, and check one on another computer, with BackDown or without it.

CLI reference

  • All commandsEvery backdown command and option, generated from the program's own help.

Help

  • Troubleshooting and FAQFiles BackDown can't read, drives that don't show up, rescans that walk, the app and the background service, updates, where the index lives, uninstalling, and common questions.
  • Privacy and safety principlesThe five rules BackDown is built on, and how the program keeps them.

Last updated · What's released, and what's next