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For example, to test features that have several users interacting. All I've come up with is multiple OS X VM's with an iOSS in each, but that seems like a sledgehammer missing the obvious right in front of me?
AFAICT, it does not support multiple instances running at the same time.
I tried two methods, but both failed.
$ open -n /Developer/Platforms/iPhoneSimulator.platform/Developer/Applications/iPhone\ Simulator.app
LSOpenURLsWithRole() failed with error -10829 for the file /Developer/Platforms/iPhoneSimulator.platform/Developer/Applications/iPhone Simulator.app.
Using an alias (http://forums.creativecow.net/thread/71/860074) brings up a dailog box saying "Only one iOS Simulator can run at a time. Please quit iOS Simulator and try again."
http://www.coderebel.com/2010/08/31/iphone_simulator
You may want to checkout this tool. I can run multiple emulators with its help in different VNC consoles with different user on my mac mini.
We have multiple Xcode developers logging on a centralized Mac and each users have own account. Each users can start a seperated Simulator window by running below command (" s should be included):
"/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/Applications/iPhone Simulator.app/Contents/MacOS/iPhone Simulator"
After simulator window is opened, runining your project will automatically attach Xcode to this window.
Only thing that I'm not sure about, I've ran below script below before. I don't know if it fixed something on our sytem that allows us to run above command: http://coderebel.com/2010/08/31/iphone_simulator
So I suggest first try the command, if it does not help, try script, fix your system, then use the command after.
来源：https://stackoverflow.com/questions/5835063/is-there-a-way-to-run-multiple-ios-simulators-at-once