Plesk: Overriding apache config

For PHP safe_mode you can do that through the control panel but not for open_basedir. You can create a file called vhosts.conf under conf directory in your domain root. This link explain it better.

The important thing is the command:-

/usr/local/psa/admin/sbin/websrvmng -u --vhost-name=<DOMAIN.TLD>

which would rebuild the apache config and add an Include directive to include the file we have just created. For subdomains, we need to create the vhost.conf under that subdomain conf directory and then run:-

/usr/local/psa/admin/sbin/websrvmng -a -v

http://forum.parallels.com/showthread.php?t=78897