I’ll try to explain it in another way. First, let’s talk about “semantics”:
Usually we assume that a tarball contains multiple files, and a gz is a single file compressed.
So a .tar.gz file is a single tarball that has been compressed.
A .gz.tar is understood to be a tarball containing a single gzipped file. But if that’s indeed what the file is, it doesn’t make much sense to tar it in the first place.
Moving on to what you really want to accomplish: you can certainly create many gz files and tar them, but we wouldn’t call it a .gz.tar file since tar doesn’t care about the format of the included files. Much like a bunch of compressed PDFs aren’t named .pdf.tar
Also, I’d like to point out that neither tarballs nor gzipped files are optimized for modifying.
I’ll try to explain it in another way. First, let’s talk about “semantics”:
Usually we assume that a tarball contains multiple files, and a gz is a single file compressed.
So a .tar.gz file is a single tarball that has been compressed.
A .gz.tar is understood to be a tarball containing a single gzipped file. But if that’s indeed what the file is, it doesn’t make much sense to tar it in the first place.
Moving on to what you really want to accomplish: you can certainly create many gz files and tar them, but we wouldn’t call it a .gz.tar file since tar doesn’t care about the format of the included files. Much like a bunch of compressed PDFs aren’t named .pdf.tar
Also, I’d like to point out that neither tarballs nor gzipped files are optimized for modifying.