BorgBackup

Scope: the other great open-source backup tool — same ideas as restic (encrypted, deduplicated, versioned), different shape. Run for real with BorgBackup 1.4.5.

How Borg differs, in one paragraph

restic treats the repository-location as a variable: the same command backs up to a local disk, SSH server, or S3 bucket. Borg is built around repositories on machines you reach by SSH, stores each backup as a named archive inside one repository, and is famously economical with disk space and RAM. Borg runs on Linux and macOS (Windows via WSL). If your backup target is "my home server, over SSH," Borg is the traditional answer; if it's "cloud storage, natively," that's restic's home turf.

Create a repository

Encryption choices come first, and Borg makes you pick:

export BORG_REPO=/mnt/backup-drive/borg-repo
borg init --encryption=repokey-blake2

repokey means the encryption key lives inside the repository, protected by your passphrase. Borg immediately — and correctly — warns you:

IMPORTANT: you will need both KEY AND PASSPHRASE to access this repo!
...
1. Export the borg key and store the result at a safe place:
   borg key export           REPOSITORY encrypted-key-backup
...
2. Write down the borg key passphrase and store it at safe place.

Do step 1. Right now, not later:

borg key export $BORG_REPO ~/borg-key-backup.txt

produces a file starting BORG_KEY ... followed by the encrypted key. Store that file and the passphrase in different safe places. Key without passphrase, or passphrase without key, is a repository you cannot open — see the encryption chapter.

Back up

borg create ::laptop-2026-10-16-1 ~/Documents

:: separates the repository (from BORG_REPO) from the archive name. Names are yours — a machine name plus a date is the convention, and {now} placeholders can generate them. A second run, same data, creates a second archive:

borg list

laptop-2026-10-16-1   Fri, 2026-10-16 18:07:54 [8a8f50cf...]
laptop-2026-10-16-2   Fri, 2026-10-16 18:07:56 [d9ff72ef...]

Watch deduplication work

borg info ::laptop-2026-10-16-2

                       Original size      Compressed size    Deduplicated size
This archive:              200.17 kB            200.33 kB                  0 B
All archives:              400.33 kB            400.67 kB            201.90 kB

Two archives representing 400 KiB of files; the second one's deduplicated size is 0 B — every chunk already existed. This is why Borg users keep years of archives.

Restore and compare

Extract restores into the current directory, recreating the original paths beneath it:

mkdir /tmp/restore && cd /tmp/restore
borg extract ::laptop-2026-10-16-2

In the test lab, the extracted files passed the same SHA-256 checksum comparison as the restic restores — all OK.

What changed between two archives:

borg diff ::laptop-2026-10-16-2 laptop-2026-10-16-3

   +120 B     -89 B [ctime: ...] [mtime: ...] home/you/data/report.txt

(note the second archive name drops the :: — a quirk that bites everyone once).

Pruning

Same shape as restic's forget/prune, one command:

borg prune --dry-run --list --keep-last 1

Keeping archive (rule: secondly #1):  laptop-2026-10-16-2 ...
Would prune:                          laptop-2026-10-16-1 ...

--keep-daily, --keep-weekly, --keep-monthly all exist too, followed by borg compact to actually reclaim space. Dry-run first, always.

Restic or Borg?

	restic	Borg
Cloud storage (S3, B2) built in	Yes	Not built in (SSH/local focus)
Windows	Native binary	Via WSL
Repository target	Disk, SSH, cloud — swappable	Disk or SSH server
Encryption key	Derived from password alone	Key file + passphrase (export the key!)
Vibe	One tool, many backends	Server-and-archive craftsman

Both are honest tools with long track records. The worst choice is the one you never get around to setting up.