You can switch off the Apache web server modules that are not critical to hosting services in Tools & Settings > Apache Modules. This will allow you to reduce server resources consumption (for example, get the smaller RAM footprint that is critical to VPS) and, as a result, provide for more hosting customers on a server.
Note that some modules are interdependent and can be switched off (on) only when the modules they depend on are off (on). For example, the cache module depends on disk_cache, file_cache, and mem_cache modules. This means that you cannot switch off the cache until its three dependent modules are off.
Caution: This feature is for advanced users only. Toggle modules only if you completely understand the consequences of your actions. Note that some modifications may reduce Apache performance or even lead to it becoming inoperable. In addition, these changes may affect certain Panel functions. For example, if you turn off mod_perl or mod_php, the Perl and PHP scripts (including webmail) will stop working on websites. This may cause a situation in which you offer a feature that does not work in a service plan.
Depending on your operating system, the following Apache modules are always enabled:
Debian or Ubuntu:
Redhat or CentOS: