{
      "Type" : "AWS::EC2::Instance", 
      "Properties" : {
        "ImageId" : { "Fn::FindInMap" : [ "AWSRegionArch2AMI", { "Ref" : "AWS::Region" }, "PV64" ]},
        "KeyName" : { "Ref" : "KeyName" },
        "InstanceType" : "m1.small",
        "SecurityGroups" : [{ "Ref" : "Ec2SecurityGroup" }],
        "BlockDeviceMappings" : [
          {
            "DeviceName"  : "/dev/sdc",
            "VirtualName" : "ephemeral0"
          }
        ]
      }
    }