Rdiff‑image
A backup system for hosts in the cloud

Overview

The rdiff‑image tools is a backup solution aimed at hosts running on a virtual machine somewhere in the cloud. It leverages the backup to provide a couple of other features useful to open source style maintenance of the host.

• It maintains two geographically and administratively separated copies of the backup. One is on the host, the other is a set of backups (eg 7 daily, 5 weekly, 6 monthly) on Amazon's S3.
• It uses rdiff to create differential backups that both minimise S3 costs and make downloading the latest set of changes to the host relatively fast.
• It can create a sanitised backup - ie a backup with confidential information in it replaced with so the restored image still boots. Eg, all passwords in /etc/shadow become "x". This allows for a form open source sysadmin'ing of the image while still keeping confidentiality.
• The unsanitised version of the sanitised data can be put in a separate backup that is encrypted with multiple GPG keys.
• Tools are provided to boot the backup in a chroot. This makes it both easy to move hosts quickly in the face of disaster, and to develop and test changes to the host offline.

As an indication of how much backing up to S3 costs, backing up a 4 Gib Debian Lenny host used by a Linux User Group to provide mailing lists, wiki, issue tracking, and planet feeds to members costs around USD$0.70 a month. It does hourly backups, and keeps a mixture of hourly, daily, weekly, monthly and bi-annual backups going back 3 years.

Documentation

Read it roughly in this order:

• README.txt,
• rdiff‑image‑cron(1),
• rdiff‑image‑get(1),
• rdiff‑image‑boot(1),
• rdiff‑image.conf(5),
• rdiff‑image‑tarutil(1),
• rdiff‑image‑backup(1),
• rdiff‑image‑s3(1).
   
• Example configuration file:
  rdiff‑image.conf.
   
• And the ring-in:
  rdiff‑image‑snap(1).
   
• And the relase notes:
  ChangeLog.txt.

Copyright and License

Rdiff-image is copyright © 2009-2014,2015,2016,2017,2018,2021 Russell Stuart. It is licensed under the GNU Affero General Public License.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

The copyright holders grant you an additional permission under Section 7 of the GNU Affero General Public License, version 3, exempting you from the requirement in Section 6 of the GNU General Public License, version 3, to accompany Corresponding Source with Installation Information for the Program or any work based on the Program. You are still required to comply with all other Section 6 requirements to provide Corresponding Source.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.

Downloading, Feedback & Contributing

Development for rdiff-image is hosted on Source forge:

• Download area, (.tar.gz, .deb, and .rpm).
• Issue tracker, bugs, features or just questions.
• Source repository.

Russell Stuart, 2014-May-30.