backup

Collection of bash scripts that can be used to create unencrypted backups which are easy to browse and restore without dedicated backup software

Features

• File-based: Backups consist of plain file copies which can be restored by any software
• Full Snapshots: Each run creates a complete directory tree which includes all current files
• Incremental: Unchanged files will not be copied again
• Hard Links: No duplicates of unchanged files, snapshots share the same files on disk

Usage

Create a snapshot of your full home directory (~) in the backup folder of the current directory (using rsync under the hood):

./backup-rsync-inc-snapshot-hardlink.sh ~ ./backup

Alternatively you can include only the ~/Documents and the ~/Pictures folder:

./backup-rsync-inc-snapshot-hardlink.sh ~ ./backup Documents Pictures

Directory Structure

Using the last command above might result in the following backup structure (example):

backup/
├── 2022-12-31/
│   ├── Documents/
│   │   └── example.txt
│   ├── Pictures/
│   │   └── christmas-2022.jpg
│   └── backup.log
├── 2023-01-07/
│   ├── Documents/
│   │   └── example.txt
│   ├── Pictures/
│   │   ├── christmas-2022.jpg
│   │   └── new-year-2023.jpg
│   └── backup.log
└── latest/
    ├── Documents/
    │   └── example.txt
    └── Pictures/
        ├── christmas-2022.jpg
        └── new-year-2023.jpg

Each snapshot folder is named after the date of the backup and contains an additional log file which documents the changes since the previous snapshot.

The contents of the latest folder are identical to the latest snapshot (here: 2023-01-07), which means that they are all hard-linked to the same set of files.

Since the christmas-2022.jpg picture probably has not changed since 2022, the latest snapshots of it will still point to the same file.

Assuming that example.txt has been changed between the two snapshots, 2022-12-31 will still be linked to the old version, while the newer snapshots will link to the updated version.

Attention: Never edit files inside one of the snapshots (unless you clearly know what you are doing)! Touching a file in one of the snapshots also affects all other snapshots which are hard-linked to the same file, which is usually not what you want.

Other Scripts

If you want to backup multiple shares from an SMB server you can have a look at backup-smb-shares.sh:

• Pre-configured (example) paths and SMB user (please modify these to match your setup)
• Asks for the SMB user's password
• Mounts all required SMB shares before performing the backup
• Unmounts all previously mounted SMB shares after the backup has finished

Additionally, there is also an older version of the script which uses cp instead of rsync. The main difference is that it will not delete files from the latest snapshot which have been deleted in the source.