Issue getting split tar.gz file to recombine and extract. Not a valid .gz archive

Question

I have a tar.gz archive that has been split apart like so -

files.tar.gz.part-aa.gz
...
...
...
files.tar.gz.part-ap.gz

I combine them using the cat command -

cat files* > files.tar.gz This combines the files into a 16 GB tar.gz file (which is expected)

If I try to run tar -zxf files.tar.gz I get the following error -

gzip: stdin: not in gzip format
tar: Child returned status 1
tar: error is not recoverable: exiting now

If I check the status of the file, I get this output -

file files.tar.gz then the output I get is weird - it says - files.tar.gz: data

Any ideas?

EDIT -

I ran some of the commands that you guys were mentioning I should try. Here are the results -

Ran the following commands on several different file parts. As you will see, the output is different for some file parts.

Command Run: gunzip files.tar.gz.part-ap.gz
Output/Response: gzip: filestar.gz.part-ap.gz: not in gzip format

Command Run: file files.tar.gz.part-ap.gz
Output/Response: files.tar.gz.part-ap.gz: data

Command Run: gzip -d files.tar.gz.part-ap.gz
Output/Response: gzip: files.tar.gz.part-ap.gz: not in gzip format

Command Run: file files.tar.gz.part-ah.gz
Output/Response: files.tar.gz.part-ah.gz: 8086 relocatable (Microsoft)

Command Run: file files.tar.gz.part-ak.gz
Output/Response: files.tar.gz.part-ak.gz: data

Thanks.

Answer 1

Intepreting the file extensions, it looks like these are compressed portions of a compressed archive; try this:

 gunzip files.tar.gz.part-??.gz
 cat files.tar.gz.part-?? > files.tar.gz
 tar xf files.tar.gz