Should be doable on consumer hardware nowadays, if you cheat by using a file system that either supports sparse files (https://en.wikipedia.org/wiki/Sparse_file

Should be doable on consumer hardware nowadays, if you cheat by using a file system that either supports sparse files (https://en.wikipedia.org/wiki/Sparse_file https://en.wikipedia.org/wiki/Sparse_file) or block-level deduplication (https://en.wikipedia.org/wiki/Data_deduplication https://en.wikipedia.org/wiki/Data_deduplication). You may need to use raw block I/O to create such file, and there will be lots of duplicated content in the archive. Also: how hard is that limit? ZIP archives have their TOC at the end of the file and allow for inserting ‘junk’ that is never referenced in the ZIP’s table of contents. Isn’t it possible to add such junk to make an archive go over that limit (assuming that your file system allows files larger than 2⁶⁴ bytes)?