Add dd_rally scenarios
diff --git a/rally/dd_rally.json b/rally/dd_rally.json
new file mode 100644
index 0000000..a3db957
--- /dev/null
+++ b/rally/dd_rally.json
@@ -0,0 +1,42 @@
+{% set flavor_name = flavor_name or "m1.medium" %}
+{% set image_name = image_name or "Ubuntu1404" %}
+{% set ext_net_name = "floating" %}
+{% set script_file = script_file or "cvp-configuration/rally/instance_test.sh" %}
+{
+    "VMTasks.boot_runcommand_delete": [
+        {
+            "args": {
+                "flavor": {
+                    "name": "{{flavor_name}}"
+                },
+                "image": {
+                    "name": "{{image_name}}"
+                },
+                "volume_args": {
+                    "size": 10
+                },
+                "floating_network": "{{ext_net_name}}",
+                "use_floating_ip": true,
+                "wait_for_ping": false,
+                "force_delete": false,
+                "command": {
+                    "interpreter": "/bin/sh",
+                    "script_file": "{{script_file}}"
+                },
+                "username": "ubuntu"
+            },
+            "runner": {
+                "type": "constant",
+                "times": 1,
+                "concurrency": 1
+            },
+            "context": {
+                "users": {
+                    "tenants": 1,
+                    "users_per_tenant": 1
+                },
+                "network": {}
+            }
+        }
+    ]
+}
diff --git a/rally/instance_test.sh b/rally/instance_test.sh
new file mode 100644
index 0000000..bf7e7a7
--- /dev/null
+++ b/rally/instance_test.sh
@@ -0,0 +1,34 @@
+additive_dd() {
+    sudo sh -c "echo '127.0.0.1 $(hostname)' >> /etc/hosts"
+    sudo mkfs.ext4 /dev/vdb > /dev/null
+    sudo mkdir -p /mnt/volume
+    sudo mount /dev/vdb /mnt/volume
+    
+    write_4k_res=`sudo -u root dd if=/dev/zero of=/mnt/volume/write_4k.dat oflag=direct bs=4k count=262144 2>&1`
+    local write_4k=`echo $write_4k_res |  awk '{print $14}'`
+
+    write_1m_res=`sudo -u root dd if=/dev/zero of=/mnt/volume/write_1m.dat oflag=direct bs=1M count=1024 2>&1`
+    local write_1m=`echo $write_1m_res |  awk '{print $14}'`
+
+    write_1g_res=`sudo -u root dd if=/dev/zero of=/mnt/volume/write_1g.dat oflag=direct bs=1G count=1 2>&1`
+    local write_1g=`echo $write_1g_res |  awk '{print $14}'`
+    cat << EOF
+    {
+      "title": "Write 4k, 1M, 1G file",
+      "description": "description",
+      "chart_plugin": "StackedArea",
+      "data": [
+        ["write_4k", ${write_4k}],
+        ["write_1M", ${write_1m}],
+        ["write_1G", ${write_1g}]]
+    }
+
+EOF
+}
+
+cat << EOF
+{
+  "additive": [$(additive_dd)],
+  "complete": []
+}
+EOF