When you attempt restore a dumpfile using gp_restore or using gpdbrestore you can encounter the below error message.
gp_restore_status_0_116_20140110113841:gzip: stdin: invalid compressed data--format violated
As indicated by the error message the issue is reported by the gzip utility , which says that it had trouble gunzip'ing the content on the zip file or the file is not in a readable format , in short the file is corrupted. So, as greenplum restore utility uses gzip tool to read the content from the zipped file, restore would also fail.
In the gzip official website , they have the program to fix CR (carriage return) bytes called "fixgz" , Try using the program on the corrupted gzip file using the steps mention on their website or using the steps below.
# wget http://www.gzip.org/fixgz.zip
# unzip fixgz.zip
# gcc -o fixgz fixgz.c
# fixgz <corrupted_gzip_backup_file>.gz <fixed_gzip_backup_file>.gz
# gunzip <fixed_gzip_backup_file>.gz OR zless <fixed_gzip_backup_file>.gz <<-- To test the gzip works
# mv <corrupted_gzip_backup_file>.gz <corrupted_gzip_backup_file>.gz.corrupted
# mv <fixed_gzip_backup_file>.gz <corrupted_gzip_backup_file>.gz <<-- This steps is to make sure the filenames are according to gpdbrestore expected file name for restoring the backup
If after running the "fixgz" the restore still fails then create a new backup dump or use the earlier/previous dump to restore the contents to the database.