Why is open_basedir set to none automatically after applying recommended settings through Performance Booster?

Question

• Why is the open_basedir PHP Setting set to none automatically after applying recommended settings via Plesk > Tools & Settings > Performance Booster? Is there a security risk?
• Is it expected that applying recommended settings through Performance Booster changes the open_basedir PHP configuration directive to none?

Answer

Disabling restriction for open_basedir increases the website loading speed significantly and according to PHP documentation keeping the restriction active doesn't provide a noticeable security benefit.

The industry standard for most of the largest web hosting companies is to have open_basedir set to none, but disabling undesired PHP functions in order to increase security instead.