mod_pagespeed is an open-source Apache module created by Google to help Make the Web Faster by rewriting web pages to reduce latency and bandwidth.
Please follow below instructions to install mod_pagespeed over Centos server.
1) Check Linux distros and the version on the server:
# uname -a
2) Download latest rpm of mod_pagespeed according to the architecture of the server
# wget https://dl-ssl.google.com/dl/linux/direct/mod-pagespeed-beta_current_x86_64.rpm
3) Install the rpm :
# rpm -i mod-pagespeed-*.rpm
4) After installation, configure installed files
# rpm -ql mod-pagespeed-beta /etc/cron.daily/mod-pagespeed /etc/httpd/conf.d/pagespeed.conf /usr/lib64/httpd/modules/mod_pagespeed.so /var/www/mod_pagespeed/cache /var/www/mod_pagespeed/files
5) Restart Apache
# service httpd restart
Inorder to upgrade the mod_pagespeed module, you must first download the latest version http://code.google.com/speed/page-speed/download.html and use of the command
# yum localinstall mod-pagespeed-*.rpm