I am looking for an RHCSA practice simulator or mock exam environment. I am of the understanding that there is not an official simulation environment for the certification. What practice simulators or mock test environments are there available? What do people use to gauge their prowess before undergoing the exam?
The closest thing Red Hat has for Mock Exam simulators are the end of chapter labs or the comprehensive reviews provided as part of the training course. While these aren't a 100% exact match to the exam format and delivery, it is good enough to give you a feel of what the questions will be like and how you might be tested and evaluated.
I will generally build my own simulations for an exam on what "might" be asked and practice looking up things I can "copy/paste/tweak/execute" from man pages or other on-system documentation. I also look to see where I can streamline my processes and cut down time to implement a given task.
The other great location for preparing for exams is looking at the topics and objectives. That gives you an idea of the information you should know and what you might be tested and evaluated on based on given exam questions. Finally, the most important thing ... whether you purchase exam prep books, build your own exam environment for simulation and testing, or finding some company that gives you one ...
Hope that helps