WSL Backup Script

This script allows you to create backups of your Windows Subsystem for Linux (WSL) home directory to a Windows location with custom filter options, deletion methods, and backup storage management. It uses the rjrssync utility for faster file synchronization.

Important: Although this script uses rjrssync, it can not perform backups to a remote location. It is only meant to be used for local backups. As a workaround you can use rjrssync to sync the backup output folder to a remote location.

Features

• Back up your WSL home directory from a specific distribution and user.
• Specify output folders and regex filters for customization.
• Manage previous backups by compressing, deleting oldest or random backups, based on settings.
• Utilizes rjrssync for improved performance even using /mnt/ and to preserve symlinks properly

Prerequisites

• Windows Subsystem for Linux (WSL) installed and configured with a desired Linux distribution.
• PowerShell 5.0 or later.
• rjrssync installed and sourced in your shell (https://github.com/Robert-Hughes/rjrssync).

Usage

1. Copy the backup_wsl.ps1 script to a desired location on your Windows machine.
2. Open PowerShell and navigate to the script location.
3. Run the script and provide the required parameters. Examples:

Using the script with inline parameters

.\backup_wsl.ps1 Ubuntu user c:\backups +projects.* 1 10 deleteRandom

Using the script with named parameters and values

\backup_wsl.ps1 -DistroName Ubuntu -UserName user -OutputFolder c:\backups -RegexFilters "+projects.*" -SavePreviousBackup $true -MaxBackupCount 10 -IfBackupFull deleteOlder

Parameters:

• -DistroName : The name of the WSL distribution you want to create a backup of.

• -UserName : The user whose home directory you want to back up.

• -OutputFolder : The folder where the backup will be stored.

• -RegexFilters : Regular expression filters for files and folders you want to include or exclude from the backup. Each filter is a '+' or '-' character followed by a regular expression. The '+'/'-' indicates if this filter includes (+) or excludes (-) matching entries. Separate multiple filters with a semicolon. If the first filter is an include (+), then only those entries matching this filter will be synced. If the first filter is an exclude (-), then entries matching this filter will not be synced. Further filters can then override this decision.

  The regexes are matched against a 'normalized' path relative to the root path of the source/dest:

  • Forward slashes are always used as directory separators, even on Windows platforms

  • There are never any trailing slashes

  • Matches are done against the entire normalized path - a substring match is not sufficient

  • '+.*\.txt;-subfolder' Syncs all files with the extension .txt, but not inside subfolder

• -SavePreviousBackup : Whether to save previous backups by compressing them. Set $true to save, $false to discard previous backups.

• -maxBackupCount : Maximum number of compressed backups to be stored.

• -ifBackupFull : What to do when the backup folder is full. Valid values are "deleteOldest", "deleteRandom", and "doNothing". Note: When using the "deleteRandom" option, the script will never delete the oldest backup.

Important Notes

• rjrssync is known to be faster when used on remote connections, but it will still be more performant than alternative tools using the usual mounting methods like \mnt\.
• Ensure that rjrssync is installed and sourced within your shell before running the script.