How to Install Two AOS's In AX

How to install Another AOS in Existing AOS , How many AOS can be possible we can Install it?

There are some msdn url which can help you:

Some best practices when you install AOS.

You can have up to 99 AOS services on a single machine, if it’s powerful enough to handle that. Just use the installation wizard again to add one more application tier. Then you’ll have to use client configurations to connect to the right AOS.