we installed several instances of LimeSurvey as they own domain on single server. These subdomains have structure of
survey.domainABC.com
survey.domainABCD.com
survey.domainABCDE.com

and so on...One of these domains is loading extremely slow and we wanted to ask if anyone can point us in the right direction. We are running CentOS, MySQL on db and PHP. Other subdomains load fine, some faster than others.

Is there any specific PHP best practices, or multi domain configuration that we need to be paying attention to. Most of our survey users will not be on the system at one time at once. Any help is much appreciated.