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What is Attic?

Attic is a deduplicating backup program. The main goal of Attic is to provide an efficient and secure way to backup data. The data deduplication technique used makes Attic suitable for daily backups since only changes are stored.

Easy to use

Initialize backup repository and create a backup archive:

$ attic init /usbdrive/my-backup.attic
$ attic create -v /usbdrive/my-backup.attic::documents ~/Documents

Main features

Space efficient storage
Variable block size deduplication is used to reduce the number of bytes stored by detecting redundant data. Each file is split into a number of variable length chunks and only chunks that have never been seen before are compressed and added to the repository.
Optional data encryption
All data can be protected using 256-bit AES encryption and data integrity and authenticity is verified using HMAC-SHA256.
Off-site backups
Attic can store data on any remote host accessible over SSH. This is most efficient if Attic is also installed on the remote host.
Backups mountable as filesystems
Backup archives are mountable as userspace filesystems for easy backup verification and restores.

What do I need?

Attic requires Python 3.2 or above to work. Besides Python, Attic also requires msgpack-python and sufficiently recent OpenSSL (>= 1.0.0). In order to mount archives as filesystems, llfuse is required.

How do I install it?

$ pip install Attic

Where are the docs?

Go to for a prebuilt version of the documentation. You can also build it yourself from the docs folder.

Where are the tests?

The tests are in the attic/testsuite package. To run the test suite use the following command:

$ fakeroot -u python -m


Deduplicating backup program







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