gzip failing to unzip

[william drescher]

To find a low frequency failure in a production system I have 
been taking periodic dumps (using phymyadmin-export) specifying 
that the file be gzipped.  It appears to have worked just fine.

Today I went to unzip  one of the files to use it as a mysql 
source on the development system so I could dig into the problem 
and..

gunzip reported:
gzip: IS-2016-12-31.sql.gz: decompression OK, trailing garbage 
ignored

The "trailing garbage" is the last 3/4 of the file.  The gzipped 
file is 17MB.

Anybody have any ideas what is going wrong and or suggestions 
that I can try to recover the data.

--bill