Can I have more than one simulator running on my Linux host at the same time?

Being able to run multiple simulators at the same time allows you to test functionality such as SnapMirror without needing another machine.

If you have enough physical memory to support your host and the memory you give to each simulator then you can run as many simulators as you like at the same time. Consider using something like vmstat in Linux to see how much memory you have available after starting each simulator.