DirectoryMesh

DirectoryMesh is a Java utility which can mesh a master directory and a data directory together.

This is pre-release software

I did my best, but you'd beta watch out. Please report any issues here: https://github.com/hollandjg/DirectoryMesh

Usage scenario

A user has several storage drives, of which one is always present and should be considered the "master" drive. This is usually a drive with insufficient capacity to store all of the data the user needs. The user also has a second drive with a larger capacity but wants to be able to access data on both drives within the master directory structure.

Solution

The user defines a sensible directory structure in master (which we assume to be the home directory):

[master]
├─── Documents
│    ├─── Applications
│    └─── Letters
├─── Projects
│    ├─── Doctorate
│    │    ├─── OldFile -> [data]/Projects/Doctorate/OldFile
│    │    └─── Thesis
│    └─── MoonlightingAsASecurityConsultant
└─── Music
     └─── DAWProjects
          └─── CurrentProject

The required subset of the structure is implemented on the data drive:

[data]
├─── Projects
│    └─── Doctorate
│         └─── LargeDataFile
└─── Music
     └─── DAWProjects
          └─── ArchivedProject

The two directories are meshed together using the shell command:

java -jar DirectoryMesh.jar --dryRun --prune -m [master] -d [data]

After checking that the correct operations are going to be performed having dealt with any conflicts, remove --dryRun to carry out the meshing operation.

A concrete example, where /Users/john is on an SSD and /Volumes/data is a large capacity external drive:

directorymesh --dryRun --prune -m /Users/john -d /Volumes/data/john

After running the mesh, the filestructure looks like this:

    [master]
    ├─── Documents
    │    ├─── Applications
    │    └─── Letters
    ├─── Projects
    │    ├─── Doctorate
    │    │    ├─── LargeDataFile -> [data]/Projects/Doctorate/LargeDataFile
    │    │    └─── Thesis
    │    └─── MoonlightingAsASecurityConsultant
    └─── Music
         └─── DAWProjects
              ├─── ArchivedProject -> [data]/Music/DAWProjects/ArchivedProject
              └─── CurrentProject

The broken link at [master]/Projects/Doctorate/OldFile has been pruned.
If any conflicts arise during the mesh, such as two regular files in the same location, the file reports the conflict and doesn't do anything with those files. DirectoryMesh continues regardless.
It should not delete any files which aren't symlinks or which are not links back to locations within [data].
Running the mesh on a directory which has already been meshed should cause no problems. New links will be added and if the --prune option is specified broken links will be removed.

Installation

Prerequisites: Java 8

Download the latest DirectoryMesh.jar from https://github.com/hollandjg/DirectoryMesh/releases/

If you're on a Mac, you can install the .jar and a wrapper script using homebrew:

brew tap hollandjg/tap 
brew install directorymesh
directorymesh --dryRun --prune -m [master] -d [data]