borgbackup/docs/usage/transfer.rst

.. include:: transfer.rst.inc

Examples
~~~~~~~~

To keep the following examples short and readable, we export the repository
locations and passphrases first:

::

    export BORG_REPO=ssh://borg2@borgbackup/./tests/b20
    export BORG_PASSPHRASE='your-borg2-repo-passphrase'
    export BORG_OTHER_REPO=ssh://borg2@borgbackup/./tests/b1x
    export BORG_OTHER_PASSPHRASE='your-borg1-repo-passphrase'

::

    # Borg 1.x repository -> Borg 2.0 repository (hmac-sha256 -> hmac-sha256, keeping the same chunk ID algorithm)

    # 0. Have Borg 2.0 installed on the client AND server; have a Borg 1.x repository copy for testing.

    # 1. Create a new "related" repository:
    # Here, the existing Borg 1.x repository used repokey (and AES-CTR mode),
    # thus we use aes256-ocb for the new Borg 2.0 repository.
    # Staying with the same chunk ID algorithm (hmac-sha256) and with the same
    # key material (via BORG_OTHER_REPO) will make deduplication work
    # between old archives (copied with borg transfer) and future ones.
    # The AEAD cipher does not matter (everything must be re-encrypted and
    # re-authenticated anyway); you could also choose chacha20-poly1305.
    $ borg repo-create -e aes256-ocb

    # 2. Check what and how much it would transfer:
    $ borg transfer --from-borg1 --dry-run

    # 3. Transfer (copy) archives from the old repository into the new repository (takes time and space!):
    $ borg transfer --from-borg1

    # 4. Check whether we have everything (same as step 2):
    $ borg transfer --from-borg1 --dry-run

::

    # Borg 1.x repository -> Borg 2.0 repository (blake2 -> blake3, changing the chunk ID algorithm)

    # 0. Have Borg 2.0 installed on the client AND server; have a Borg 1.x repository copy for testing.

    # 1. Create a new "related" repository:
    # Here, the existing Borg 1.x repository used repokey-blake2 (and AES-CTR mode),
    # thus we use aes256-ocb with --id-hash blake3 for the new Borg 2.0 repository.
    # We need to change from blake2 to blake3, because blake2 is not supported
    # for borg2 repos (blake3 is much faster). Because we change how chunk IDs are
    # computed, we need to re-chunk everything while doing the transfer.
    # The chunker parameters you provide here should be the same as you will
    # use for all future Borg 2.0 archives.
    # The AEAD cipher does not matter (everything must be re-encrypted and
    # re-authenticated anyway); you could also choose -e chacha20-poly1305 -i blake3.
    $ borg repo-create -e aes256-ocb -i blake3
    $ export CHUNKER_PARAMS="buzhash64,19,23,21,4095"

    # 2. Check what and how much it would transfer:
    $ borg transfer --from-borg1 --chunker-params=$CHUNKER_PARAMS --dry-run

    # 3. Transfer (copy) archives from the old repository into the new repository (takes time and space!):
    $ borg transfer --from-borg1 --chunker-params=$CHUNKER_PARAMS

    # 4. Check whether we have everything (same as step 2):
    $ borg transfer --from-borg1 --chunker-params=$CHUNKER_PARAMS --dry-run

Keyfile considerations when upgrading from Borg 1.x
++++++++++++++++++++++++++++++++++++++++++++++++++++

If you are using a ``keyfile`` encryption mode (not ``repokey``), Borg 2
may not automatically find your Borg 1.x key file, because the default
key file directory has changed on some platforms due to the switch to
the `platformdirs <https://pypi.org/project/platformdirs/>`_ library.

On **Linux**, there is typically no change -- both Borg 1.x and Borg 2
use ``~/.config/borg/keys/``.

On **macOS**, Borg 1.x stored key files in ``~/.config/borg/keys/``,
but Borg 2 defaults to ``~/Library/Application Support/borg/keys/``.

On **Windows**, Borg 1.x used XDG-style paths (e.g. ``~/.config/borg/keys/``),
while Borg 2 defaults to ``C:\Users\<user>\AppData\Roaming\borg\keys\``.

If Borg 2 cannot find your key file, you have several options:

1. **Copy the key file** from the old location to the new one.
2. **Set BORG_KEYS_DIR** to point to the old key file directory::

       export BORG_KEYS_DIR=~/.config/borg/keys

3. **Set BORG_KEY_FILE** to point directly to the specific key file::

       export BORG_KEY_FILE=~/.config/borg/keys/your_key_file

4. **Set BORG_BASE_DIR** to force Borg 2 to use the same base directory
   as Borg 1.x::

       export BORG_BASE_DIR=$HOME

   This makes Borg 2 use ``$HOME/.config/borg``, ``$HOME/.cache/borg``,
   etc., matching Borg 1.x behavior on all platforms.

See :ref:`env_vars` for more details on directory environment variables.