Let’s think about a situation where you have a subdomain and you want it to be able to access files from the domain httpdocs directory. You cannot do that by default in Plesk, because of open_basedir. You can edit the httpd.include file in:
but that will only work until the next plesk restart or major modification.
But, the httpd.include file that manages a domain and subdomain explicitly says:
# DO NOT MODIFY THIS FILE OR ANY PART OF IT. THIS CAN RESULT IN IMPROPER PLESK
# FUNCTIONING OR FAILURE, CAUSE DAMAGE AND LOSS OF DATA. IF YOU REQUIRE CUSTOM
# MODIFICATIONS TO BE APPLIED TO THE CONFIGURATION, PLEASE, PERFORM THEM IN THE
# FOLLOWING FILE(S):
So, disabling open_basedir is *usually* as simple as editing the vhost.conf file (or create it if it does not exist), and adding: