Linsh.rar

If you provide this info, I can tell you if you should be using the rar command-line tool or if a simple right-click in Windows will do the trick. rar - ArchWiki

Optional: Select a "Best" compression method for higher compression. Click OK to generate the solid archive. Key Considerations for Solid Archives:

Adding or extracting single files from a solid archive takes much longer because the entire archive must be processed. Linsh.rar

Right-click the folder or files you want to archive.

Are you trying to create or turn multi-part files (.part1, .part2) into one ? If you provide this info, I can tell

Many small, similar files, as it treats them as a single stream to boost compression.

To create a "solid" piece (or a solid archive) from your Linsh.rar data, you are essentially treating all compressed files as a single data block to increase compression efficiency. This is best achieved using on Windows, as solid mode is a native RAR feature. Here is how to create a solid RAR file: Key Considerations for Solid Archives: Adding or extracting

In the "General" tab, set to RAR (Solid mode only works with RAR, not ZIP). Check the box for "Create solid archive" .