$ gunzip archive.gz
.gz is files are compressed with gzip in linux. To extract .gz files we use gunzip command.
First use following command to create gzip (.gz) archive of access.log file. Keep remember that below command will remove original file.
Above command will create a archive file named access.log.gz in current directory.
ls -l access.log.gz -rw-r--r-- 1 root root 37 Sep 14 04:02 access.log.gz
Now use gunzip command to extract access.log.gz file using command. This will extract the file from archive and remove .gz file automatically.