Hello PerserPolis-1732,
I want to have a second SCCM site server to deploy from both server. I am not sure what is the best method for that.
If you mean download the content from two different locations, you can setup two different distribution points, then your clients will download the content (application installer, packages, software updates etc) from the nearest DP to save network bandwidth.
Take a look of the following Size & Scale documentation to adapt your SCCM architecture within your need & infrastructure.
What I want to have, is on fact Site Server High Availability too. What is the best practice?
To setup site server HA, there are multiple requirements to be set, such as SQL DB in Always On, shared library content and so on. You will find more details in the following documentation:
Regards,
Youssef Saad | Blog: https://youssef-saad.blogspot.com/ | LinkedIn