We recommend that our customers create a developer partition and install a developer licensed copy of Zend Server for IBM i on that partition. This is the best way to test upgrades and additions to your PHP applications. The new code can first be tested on the developer partition to verify that the new code will run well in production. This is also the best way to test Zend Server for IBM i upgrades.
We do appreciate that for some customers adding a new partition is not considered an economical option. However, our understanding is that these configurations have become more affordable over time. If economics have prevented a customer from configuring a developer partition in the past, it may be worth revisiting the idea with their IBM hardware and software vendor, to see what options they can offer.