Question

I have been looking around if Gzip supports multi-part file compression. From what I have seen so far it does not, but how come 7z allows multipart compression when Gzip is selected as the compression? Does this mean 7z takes care of multi-partitioning internally?

Answer 1

Gzip doesn’t support multipart archives, but you can still create them using split:

split -–bytes=20m /path/to/large/archive /path/to/output/files

Now, to put it back together, just cat the parts together into one:

cat files* > archive

As far as I can tell, this is what 7-zip does when creating archives. It might add some header information, but it basically just dumps exactly 20mb of data into a file and appends a number after the name. Then, internally, it just assembles the parts and reads that as an archive.