Rsync Time Machine

A Time Machine-like backup utility using rsync that creates space-efficient snapshots with versioning.

Features

• Incremental backups using rsync
• Space-efficient storage using hard links
• Snapshot-based versioning
• Automatic archiving of deleted/changed files
• Detailed logging of all operations

Requirements

• macOS with Homebrew
• rsync (installed via Homebrew)
• Common macOS utilities (date, mkdir, ln, rm)

Installation

1. Ensure rsync is installed:

brew install rsync

2. Clone or download this repository
3. Make the script executable:

chmod +x rsync-time-machine.sh

Usage

./rsync-time-machine.sh -s SOURCE_DIR -b BACKUP_DIR [-n]

Options

• -s, --source-top-dir SOURCE: Directory to backup
• -b, --backup-top-dir TARGET: Directory where backups will be stored
• -n, --dry-run: Perform a trial run without making any changes
• -h, --help: Display help message

Example

./rsync-time-machine.sh -s /Users/me/Documents -b /Volumes/Backup/TimeMachine

Backup Structure

The backup directory will contain:

• _MIRROR/: The main backup directory containing the latest snapshot
• __ARCHIVE/: Contains previous versions of modified/deleted files
• __LOGS/: Detailed logs of each backup operation
• .__SHADOW/: Internal directory used for detecting moves and renames

Notes

• The script automatically creates all necessary directories
• Each backup operation generates a detailed log file
• Hidden files (starting with '.') are excluded by default
• Files deleted from the source are moved to the archive instead of being deleted

TODO

• add option for 2 separate backup modes:
  • 1] single current mirror + deleted archive
    • (currently implemented) this style maintains a single snapshot of the current state of the folder as it appears when backed up. only deleted or changed files are moved to a timestamped archive folder for retrival if needed.
  • 2] many full-directory snapshot backups
    • this style more directly mirrors Apple's Time Machine utility there are separate timestamped snapshot folders that include the entire filetree of the source folder as it appeared when backed up.