Add dd_rally scenarios
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