Steps to install
cd /root yum install at wget https://dl-ssl.google.com/dl/linux/direct/mod-pagespeed-stable_current_x86_64.rpm
rpm -i --nodeps mod-pagespeed-stable_current_x86_64.rpm
Now we have to edit some files.
add this line: Include /etc/httpd/conf.d/pagespeed.conf
remove this line or comment it: Include conf/extra/httpd-deflate.conf
Make sure there is no ‘setoutputfilter’ line in your .htaccess file, this will interfere with mod_pagespeed.
Now restart httpd and see if you’ve got the module loaded:
service httpd restart apachectl -t -D DUMP_MODULES
Check if you see “pagespeed_module (shared)” loaded.