Rewrite rules (and all directives) are placed in the vhost definition. I believe (in the Centmin mod) those files are kept under /home/nginx/domains/ and then appropriate name configured.
Agreed. For me the simplicity of including it in the file vhost definition itself helps on following the logic without having to go into a second file to look.
I haven't played with PHP 5.5 yet (waiting for it to be "stable" and shipped out as a Debian package). I know that with some of the cache's you have to define a memory footprint for it to use. Is Zend OpCache the same?
Have you reviewed http://stackoverflow.com/questions/17224798/how-to-use-php-opcache?
zend_extension=/full/path/to/opcache.so
; Sets how much memory to use
opcache.memory_consumption=128
;Sets how much memory should be used by OPcache for storing internal strings
;(e.g. classnames and the files they are contained in)
opcache.interned_strings_buffer=8
; The maximum number of files OPcache will cache
opcache.max_accelerated_files=4000
;How often (in seconds) to check file timestamps for changes to the shared
;memory storage allocation.
opcache.revalidate_freq=60
;If enabled, a fast shutdown sequence is used for the accelerated code
;The fast shutdown sequence doesn't free each allocated block, but lets
;the Zend Engine Memory Manager do the work.
opcache.fast_shutdown=1
;Enables the OPcache for the CLI version of PHP.
opcache.enable_cli=1
