Amazon EC2 asterisk memory issue

Hello! I wrote my problem yesterday
viewtopic.php?f=1&t=90575

and david helped me ! So now I know the problem!

I installed asterisk in my computer it has no problem … the problem is asterisk in EC2…
and I read that "VM must be configured with enough dedicated RAM for all Asterisk’s needs…"
what it means? and how I can do that?? T.T