snapm 0.5.0

Snapshot Manager

Snapm

Snapshot manager (snapm) manages named snapshot sets on Linux systems. Each snapshot set captures coordinated snapshots across multiple volumes, representing a consistent point-in-time system state that can be referenced and managed as a single unit.

Features

• Coordinated snapshot sets: Create coordinated snapshots across multiple volumes
• Bootable snapshots: Generate boot entries for snapshot boot and failsafe revert
• Multiple backends: Support for LVM2 (Copy-on-Write and Thin) and Stratis
• Flexible scheduling: Integration with systemd timers for automated snapshot creation with retention policies
• Size policies: Flexible snapshot sizing with multiple strategies
• Plugin architecture: Extensible design for additional storage backends

Quick Start

Installation

From RPM (Fedora/CentOS/RHEL)

Install from distribution repositories (when available):

dnf install snapm boom-boot

Manual Installation

1. Create and activate a virtual environment:

python3 -m venv --system-site-packages .venv && source .venv/bin/activate

2. If boom-boot is not installed from your distribution's packages, clone and install it with pip:

git clone https://github.com/snapshotmanager/boom-boot.git
cd boom-boot
python3 -m pip install .

3. Repeat the process with the snapm repository:

git clone https://github.com/snapshotmanager/snapm.git
cd snapm
python3 -m pip install .

Basic Usage

Create a bootable snapshot set

Create a snapshot set named "before-upgrade" of root and home, with snapshot boot and revert boot entries:

snapm snapset create --bootable --revert before-upgrade / /home

List snapshot sets

snapm snapset list

Show detailed information:

snapm snapset show before-upgrade

Boot into a snapshot

• Reboot and select the snapshot boot entry from the GRUB menu
• Entry will be named: "Snapshot before-upgrade YYYY-MM-DD HH:MM:SS (version)"
• Optionally run grub2-reboot <title> to pre-select snapshot boot entry, e.g.:

grub2-reboot "Snapshot before-upgrade YYYY-MM-DD HH:MM:SS (version)"

• Use grub-reboot instead of grub2-reboot on Debian and Ubuntu systems.

Revert to snapshot state

snapm snapset revert before-upgrade

Then reboot into the Revert boot entry.

Note: Reverting destroys the snapshot set (snapshots are merged back into the origin volumes).

Clean up

Delete snapshot set when no longer needed:

snapm snapset delete before-upgrade

Common Workflows

System Updates

Before major system updates:

snapm snapset create --bootable --revert pre-update / /var

If update goes wrong, revert:

snapm snapset revert pre-update

When satisfied with update, clean up:

snapm snapset delete pre-update

Development Snapshots

Quick development checkpoint:

snapm snapset create dev-checkpoint /home /var

Continue working...

If needed, revert specific volumes by splitting them into a dedicated snapshot set first:

snapm snapset split dev-checkpoint dev-checkpoint-home /home

Example output:

SnapsetName:      dev-checkpoint-home
Sources:          /home
NrSnapshots:      1
Time:             2025-08-30 12:44:00
UUID:             ee82269f-8c78-5814-b47a-b9be31bcebb5
Status:           Inactive
Autoactivate:     no
Bootable:         no

snapm snapset revert dev-checkpoint-home

Alternatively revert the entire snapshot set:

snapm snapset revert dev-checkpoint

Documentation

• User Guide - Comprehensive usage documentation
• API Documentation - Auto-generated API docs
• Manual Pages - System manual pages

Requirements

• Linux system with LVM2 or Stratis volumes
• boom-boot
• Root privileges for performing storage operations
• Python 3.9+

Supported Storage Backends

Backend	Type	Snapshots	Thin Provisioning	Status
LVM2	Copy-on-Write	✓	✗	Stable
LVM2 Thin	Thin Pools	✓	✓	Stable
Stratis	Thin Pools	✓	✓	Stable

Contributing

We welcome contributions! Please see CONTRIBUTING.md for guidelines.

Support

• GitHub Issue Tracker
• User Guide
• API Docs

License

Licensed under the Apache License, Version 2.0. See LICENSE for details.

Related Projects

• boom - Boot manager for Linux snapshot boot
• stratis-cli - Command-line tool for Stratis storage
• lvm2 - The LVM2 logical volume manager