VIRTUAL FILE SYSTEM INFORMATION

Content forMicrosoft Flight Simulator 2024 is distributed through add-on packages. Each package includes multiple folders and files organized in a very specific way which allows the simulator to identify and load the package contents, along with the packages of other developers (including those of the simulation itself). All packages will bestored in one of three different locations depending on their origin and nature, all found - by default - in the <USERS>\AppData\Roaming\Microsoft Flight Simulator 2024\Packages\ folder:

• Official2020: for MSFS 2020 packages downloaded from the Marketplace.
• Official2024: for MSFS 2024 packages downloaded from the Marketplace.
• Community:for MSFS 2020packages downloaded from outside of the Marketplace.
• Community2024: for MSFS 2024packages downloaded from outside of the Marketplace.

 

You can explore the contents of these folders, using theVirtual File Systemtool.

 

 

Content loading

Packages are installed ("mounted") into the simulator through its Virtual File System (shortened to VFS), which acts as a single giant virtual hard drive aggregating all folders and files together within a common hierarchy. For example, say we have two packages set up as follows:

+ mycompany-package-1
+ folder 1
- file1
- file2
- file3

+ mycompany-package-2
+ folder 2
- file1
- file2
- file4

 

Once these packages are installed on theVFS, the structure will look like this:

+ root
+ folder 1
- file1
- file2
+ folder 2
- file1
- file2
- file3
- file4

 

 

Package Type Hierarchy

The example above shows the basic idea about how packages are merged when they are mounted, but there is an additional layer involved, which is packagetype hierarchy. Packages of different types are mounted to specific locations within theVFSfor the simulator to be able to identify and load their contents correctly. This hierarchy is complicated and will depends on the asset typescontained within the package, but to give an example, here's how SimObjects are placed within the VFS:

+ root
+ SimObjects
+ airplanes
+ animals
+ boats
+ groundvehicles
+ humans
+ landmarks
+ misc
+ proceduralcharacters

 

The other different package types will have a similar structure (ie: scenery, POI's, model libraries, etc...). Note that you can see the VFS hierarchy at any time by using theVFS Projector.

 

 

Package Mount Order

All files are mounted within a strict hierarchy in the VFS, and will always be placed in the same locations depending on asset type. However, theorderin which they are mounted in the VFS will depend on a number of factors, all of which should be taken into consideration, especially when you start to look into the VFS override functionality (explained below). The following rules will be applied when mounting a package:

• When the same package is in both an Official folder (streamed or not) and a Community folder, the latter is used.
• Packages are mounted in the order given by their Package Order Hint.
• Within a group of packages with the samepackage order hint:
  • Packages are mounted in the alphabetical order.
  • A newly mounted package has priority over previously mounted ones.
  NOTE: This means that - by default - a package starting with Z has priority over a package starting with A.

 

 

VFS Overriding

When multiple packages include a file that would end up mounted in the same location in the VFS, the package priority defined above is used to determine which one should be used. This is the way that files override each other automatically as they are mounted in the VFS. However, a few locations in the VFS require that the files you intend to override are listed as Globally Overriden Fileswithin the package. These are:

• All files in html_ui
• All files in ModelBehaviorDefs

 

You can find more information about how these locations can be overriden from the following page:

• Globally Overriden Base Sim Files