Dsf.7z

If a .dsf file is itself a 7z-compressed archive (sometimes indicated by a .dsf.7z extension or simply renamed), you can rename it back to .7z to extract it. :

A container format used by X-Plane to store scenery data, including mesh, terrain, and objects. It is designed to be extensible, allowing new features to be added without changing the base file format. DSF.7z

For developers and advanced users of flight simulators, managing these files involves a specific workflow: : DSF.7z

Default; provides high compression and fast decompression for most data. DSF.7z

A high-compression file format. Using 7-Zip on DSF files can significantly reduce their size, which is critical for large scenery packages. How to Work with DSF.7z Files