Backup utilities

This repository contains simple but effective backup utilities for Linux servers.

Features:

• Data that shall be backed up is pulled from the server to the backup destination, so that no extra utilities (except ssh and rsync) need to be installed on the backed-up machine.
• Backups are rotated in daily, weekly, monthly, and yearly cycles. The number of retained backups per cycle can be configured. Each cycle can be disabled.
• All backups are incremental, which saves disk space (that is, if a file has not been changed, it will not be backed up again).
• Backups heavily rely on hard-links, a feature that is natively provided by many file systems. That means: no proprietary backup/compression/indexing format; all backups are saved as regular files to the disk. To recover a backup, it is enough to just copy the files contained in the folder representing the respective backup.
• No heavy dependencies: scripts are written in Bash, and only rely on rsync for copying files.

dirbak

dirbak creates a file-wise back-up of the entire source directory at the given destination. The back-up is created using hard links, so that the back-up is a full back-up (independent from other back-ups), but creates a hard link to a file if it already exists in another back-up. That way, no redundant copying is made. The source directory and its contents will be linked to a newly created directory in $DESTINATION that is named after the current date by default, in YYYY-MM-DD format (even though the name can be changed).

When dirbak is run multiple times, a typical directory structure will look like this, for example:

backupfolder/
├─ 2018-01-01/
│  ├─ README.md
│  └─ src/
│     ├─ main.rs
│     └─ Cargo.toml
├─ 2018-01-02/
│  ├─ README.md
│  └─ src/
│     ├─ demo/
│     │  └─ mod.rs
│     ├─ main.rs
│     └─ Cargo.toml
├─ 2018-01-03/
│  ├─ README.md
│  └─ src/
│     ├─ demo/
│     │  ├─ test.rs
│     │  └─ mod.rs
│     ├─ main.rs
│     └─ Cargo.toml
└─ last [symlink to ./2018-01-03/]

All files that have not changed between the individual updates, hard-link to the same inode on the hard-disk (and thus consume almost no disk space).

The tool is used as

dirbak [OPTIONS] SOURCE DESTINATION

where:

• SOURCE is the source directory that shall be backed up. It can be a local path or a remote one (via SSH); in the latter case, it needs to be in a format accepted by rsync (e.g. user@host:/path/to/dir).
• DESTINATION is the destination direcory in which all backups are stored. It must be a local path.
• The option --name= allows you to specify a custom name for the backup. By default, it will be the current date in YYYY-MM-DD format.
• The option --exclude= (can occur multiple times) allows you to exclude a source file or folder from being backed up. All --exclude flags are directly passed to rsync.

rot

rot is an utility that rotates a given file or folder by creating daily, weekly, monthly and yearly hard-links in dedicated folders in the output directory. It only keeps a given number of copies for the daily, weekly, monthly and yearly links; all older links will be deleted. Links will be named after the current date in the format YYYY-MM-DD (daily), YYYY-WW (weekly), YYYY-MM (monthly) and YYYY (yearly), respectively. Optionally, a prefix and a suffix for the created links can be specified.

A typical folder structure will look like the following:

rotfolder/
├─ daily/
│  ├─ 2018-01-01/
│  ├─ 2018-01-02/
│  ├─ 2018-01-03/
│  ├─ 2018-01-04/
│  └─ 2018-01-05/
├─ weekly/
│  ├─ 2017-50/
│  ├─ 2017-51/
│  ├─ 2017-52/
│  ├─ 2018-01/
│  └─ 2018-02/
├─ monthly/
│  ├─ 2017-09/
│  ├─ 2017-10/
│  ├─ 2017-11/
│  ├─ 2017-12/
│  └─ 2018-01/
└─ yearly/
   ├─ 2016/
   ├─ 2017/
   └─ 2018/

The tool is used as

rot [OPTIONS] PATH

where:

• PATH is the path to the file or folder that shall be rotated. The file/folder itself will not be touched; only (recursive) hard links will be made. The path must be local.
• The option --name= allows you to specify a custom name for the backup. By default, it will be the current date in YYYY-MM-DD format.
• The option --exclude= (can occur multiple times) allows you to exclude a source file or folder from being backed up. All --exclude flags are directly passed to rsync.
• The option --daily-num specifies the number of daily copies that are kept.
• The option --weekly-num specifies the number of weekly copies that are kept.
• The option --monthly-num specifies the number of monthly copies that are kept.
• The option --yearly-num specifies the number of yearly copies that are kept.
• The option --prefix specifies the prefix that shall be prepended to the file name of the links.
• The option --suffix specifies the suffix that shall be appended to the file name of the links. Useful for specifying a file extension.
• The option --out specifies the folder in which the rotation copies are created (the folder which contains the daily/, weekly/, monthly/ and yearly/ sub-folders.
• The option --daily-out allows you to given another name to the daily/ subfolder.
• The option --weekly-out allows you to given another name to the weekly/ subfolder.
• The option --monthly-out allows you to given another name to the monthly/ subfolder.
• The option --yearly-out allows you to given another name to the yearly/ subfolder.
• The option --now specifies the date that shall be used to deduce the names of the rotation folders. Needs to be in a format that is accepted by date.
• If the option --no-create-daily is set, no daily copies are created.
• If the option --no-create-weekly is set, no weekly copies are created.
• If the option --no-create-monthly is set, no monthly copies are created.
• If the option --no-create-yearly is set, no yearly copies are created.
• If the option --no-delete-daily is set, no daily copies are deleted.
• If the option --no-delete-weekly is set, no weekly copies are deleted.
• If the option --no-delete-monthly is set, no monthly copies are deleted.
• If the option --no-delete-yearly is set, no yearly copies are deleted.

Examples

Some example scripts are provided in ./examples/ that show how these scripts can be used in practise. There are currently three examples:

• backup-files.sh: Backup of a folder on a remote server, and daily/weekly/monthly/yearly rotation of this backup.
• backup-mysql.sh: Backup of a MySQL dump on a remote server, and daily/weekly/monthly/yearly rotation of this dump.
• backup-mysql-docker.sh: The same MySQL dump script, but this time for a MySQL server running in a Docker container.

License

These utilities have been developed by Steve Muller and are licensed under an MIT license. See the LICENSE file for more information.