On one Linux Server running Apache and PHP 5, we got multiple Virtual Hosts with separate logfiles and everything. The only thing we cannot seem to separate between virtual hosts is the php
To set the Apache (not the PHP) log, the easiest way to do this would be to do:
<VirtualHost IP:Port> # Stuff, # More Stuff, ErrorLog /path/where/you/want/the/error.log </VirtualHost>
If there is no leading "/" it is assumed to be relative.