Is there a maximum filesystem size, number of CPUs associated with the different Centos versions? If so, is there a way for me to have them upgraded?
Yes, you can upgrade the cantos version for all the system you have. For upgrading the CPUs connect them with a network connection and make a backup for all the data you did not want to lose. The new version will delete all the existing settings of your system. Use the following tools to backup your data to other server you have:
Use mysqldump for MySQL databases
Use pg_dump for PostgreSQL databases
Use tar and rsync tool for LAMP
Type the following to get the update:
# yum list updates
To upgrade the box type
# yum update
To reboot the server type
# reboot
To verify everything is working type
# uname -a
# netstat -tulpn
# tail -f /var/log/messages
# tail -f /path/to/log/file
# cat /etc/redhat-release
For further support see: https://www.cyberciti.biz/faq/upgrade-centos-linux/
