The first thing nano-backup shows you when you do a backup, is what has changed since the last backup. This allows you to review all the files you have tinkered with before committing them to your repository. The goal here is to enable a fast review, restore and commit cycle, giving you precise control about the state of your system.

Nano-backup focuses only on local backups. It does not support cloud providers, encryption, compression or granular chunk/delta based deduplication. It only implements whole-file deduplication. Encryption can be achieved by backing up to a LUKS partition.

Installation

Nano-backup depends only on a C compiler and a POSIX.1-2001 compliant operating system. Run the following command from inside the projects directory:

./scripts/build-release.sh
sudo cp ./build/nb /usr/local/bin/

Usage

A repository is a directory with a file named config inside it:

mkdir repo/
vi repo/config

Here is an example config:

[mirror]
/home/user/Videos
/home/user/Pictures

The first line sets the mirror policy. The other lines are absolute paths to files or directories which should be backed up. To do a backup, pass the repository to nano-backup:

nb repo/

To prevent files from being backed up, set the ignore policy. This allows specifying regular expressions, which will be matched against full, absolute filepaths. They must be valid POSIX extended regular expressions:

[ignore]
\.pyc$
^/home/user/.*/__pycache__$

Regular expressions can also be used for matching files you want to backup. Just prefix a pattern with an additional slash:

[mirror]
/home/user//\.(png|jpg)$
/home//^(foo|bar)$/.bashrc

Note: These expressions will not match recursively and can be terminated by a slash.

Restoring files

Files can be restored like this:

nb repo/ 0 file.txt

0 is the id of the latest backup. The backup before it would be 1, etc.

Note: This number will be ignored for copied/mirrored files, which will always be restored to their latest state.

Policies

Policies specify how files should be backed up. They apply only to the last element of a path, but will match all files inside it recursively:

[policy]
/home/user/last-element

Policy name	Description
copy	Backup only the latest version of a file.
mirror	Like copy, but if a file gets removed from the system, it will also be removed from the backup.
track	Keep a full history of every change.
ignore	Allows specifying regular expressions for excluding paths.
summarize	Allows specifying regular expressions for directories which should not be listed recursively during backups.

Frequently asked questions

How do I synchronize two repositories?

cp -rn current/* old/
cp current/{config,metadata} old/
nb old/ gc

Can I run a hook before/after each backup?

No, write a wrapper script instead:

#/bin/sh -e

... # Run stuff before the backup.

nb "$HOME/backup"

... # Run stuff after the backup.

Can I tell it to do automatic backups once a day?

No, this is the task of tools like cron.