zfspace

Console tool to find occupied pool space in ZFS on Linux. The tool uses pure python3 with shell commands to collect useful information from ZFS and show it in convenient way wit recommendations how to free some space.

Introduction

ZFS is a non-trivial LVS filesystem with snapshots, reservations, deduplication, filesystems hierarchy and so on. Common tools, such as df or ls can't provide relevant information when you need to free some space. There is an explanatory article about this.

Snapshots USED space is another puzzle. ZFS only shows space freed by destroying individual snapshot or space occupied by all filesystem snapshots. If you add up all USED by the snapshots space, you will not get total occupied space because there is some space occupied by snapshot combinations. Most people do not comprehend this.

zfspace tries to analyze space usage and describe it in a human way with recommendations on the things you can do to free some space. The snapshot analysis is similar to this tool.

Installation

pip3 install zfspace zfspace doesn't require root priviledges as it is installed in ~/.local/bin/
If you install zfspace on a fresh server as a first python console tool, you need to restart your session to load new user PATH updated by pip.

Usage

Usage: zfspace [-h] [-V] [-f FILTER] dataset_name
Run zfspace -h to get more help
Example: zfspace mypool/root/

Compatibility

zfspace is pure python module installed by pip, so it might work on any Linux with Python3 and pip package manager. But zfspace has only been tested on Ubuntu 18.04 and Debian 10.

Development

• You must obey PEP8 formatting rules written in .flake8
• You must create new versions using bump2version. It simultaneously update several files with new version and place a version tag in repository.
  Example:

bump2version patch

or

bump2version minor

• Packet release is based on pyproject.toml. First prepare your environment with:

pip3 install build

To build a packet use bump2version first and then go into project directory and run:

python3 -m build --wheel

Install manually (replace x.x.x with correct version) with:

pip install dist/zfspace-x.x.x-py3-none-any.whl --force-reinstall

Publishing notes

Twine packet must be installed

pip3 install twine

To publish:

twine upload dist/zfspace-x.x.x-py3-none-any.whl

You will be asked for login and password on PyPi.