diff --git a/devstack/lib/ironic b/devstack/lib/ironic
index b712a65377..a4906685bf 100644
--- a/devstack/lib/ironic
+++ b/devstack/lib/ironic
@@ -102,6 +102,7 @@ IRONIC_VM_COUNT=${IRONIC_VM_COUNT:-1}
 IRONIC_VM_SPECS_CPU=${IRONIC_VM_SPECS_CPU:-1}
 IRONIC_VM_SPECS_RAM=${IRONIC_VM_SPECS_RAM:-1024}
 IRONIC_VM_SPECS_DISK=${IRONIC_VM_SPECS_DISK:-10}
+IRONIC_VM_SPECS_DISK_FORMAT=${IRONIC_VM_SPECS_DISK_FORMAT:-qcow2}
 IRONIC_VM_EPHEMERAL_DISK=${IRONIC_VM_EPHEMERAL_DISK:-0}
 IRONIC_VM_EMULATOR=${IRONIC_VM_EMULATOR:-/usr/bin/qemu-system-x86_64}
 IRONIC_VM_NETWORK_BRIDGE=${IRONIC_VM_NETWORK_BRIDGE:-brbm}
@@ -711,7 +712,7 @@ function create_bridge_and_vms {
         sudo su $STACK_USER -c "$IRONIC_SCRIPTS_DIR/create-node.sh $vm_name \
             $IRONIC_VM_SPECS_CPU $IRONIC_VM_SPECS_RAM $IRONIC_VM_SPECS_DISK \
             amd64 $IRONIC_VM_NETWORK_BRIDGE $IRONIC_VM_EMULATOR \
-            $vbmc_port $log_arg" >> $IRONIC_VM_MACS_CSV_FILE
+            $vbmc_port $log_arg $IRONIC_VM_SPECS_DISK_FORMAT" >> $IRONIC_VM_MACS_CSV_FILE
         vbmc_port=$((vbmc_port+1))
     done
     create_ovs_taps
diff --git a/devstack/tools/ironic/scripts/configure-vm.py b/devstack/tools/ironic/scripts/configure-vm.py
index 51cee5fbf6..acb915a697 100755
--- a/devstack/tools/ironic/scripts/configure-vm.py
+++ b/devstack/tools/ironic/scripts/configure-vm.py
@@ -76,6 +76,8 @@ def main():
                         help='File to log console')
     parser.add_argument('--emulator', default=None,
                         help='Path to emulator bin for vm template')
+    parser.add_argument('--disk-format', default='qcow2',
+                        help='Disk format to use.')
     args = parser.parse_args()
     with file(templatedir + '/vm.xml', 'rb') as f:
         source_template = f.read()
@@ -90,6 +92,7 @@ def main():
         'network': args.network,
         'nicdriver': args.libvirt_nic_driver,
         'emulator': args.emulator,
+        'disk_format': args.disk_format
     }
 
     if args.emulator:
diff --git a/devstack/tools/ironic/scripts/create-node.sh b/devstack/tools/ironic/scripts/create-node.sh
index 4fc9cf01f5..ce3ff1f238 100755
--- a/devstack/tools/ironic/scripts/create-node.sh
+++ b/devstack/tools/ironic/scripts/create-node.sh
@@ -26,6 +26,7 @@ BRIDGE=$6
 EMULATOR=$7
 VBMC_PORT=$8
 LOGDIR=$9
+DISK_FORMAT=${10}
 
 LIBVIRT_NIC_DRIVER=${LIBVIRT_NIC_DRIVER:-"virtio"}
 LIBVIRT_STORAGE_POOL=${LIBVIRT_STORAGE_POOL:-"default"}
@@ -50,7 +51,7 @@ if [ -n "$LOGDIR" ] ; then
 fi
 
 PREALLOC=
-if [ -f /etc/debian_version ]; then
+if [ -f /etc/debian_version && "$DISK_FORMAT" == "qcow2" ]; then
     PREALLOC="--prealloc-metadata"
 fi
 
@@ -59,12 +60,12 @@ if [ -n "$LOGDIR" ] ; then
 else
     VM_LOGGING=""
 fi
-VOL_NAME="${NAME}.qcow2"
+VOL_NAME="${NAME}.${DISK_FORMAT}"
 
 if ! virsh list --all | grep -q $NAME; then
     virsh vol-list --pool $LIBVIRT_STORAGE_POOL | grep -q $VOL_NAME &&
         virsh vol-delete $VOL_NAME --pool $LIBVIRT_STORAGE_POOL >&2
-    virsh vol-create-as $LIBVIRT_STORAGE_POOL ${VOL_NAME} ${DISK}G --format qcow2 $PREALLOC >&2
+    virsh vol-create-as $LIBVIRT_STORAGE_POOL ${VOL_NAME} ${DISK}G --format $DISK_FORMAT $PREALLOC >&2
     volume_path=$(virsh vol-path --pool $LIBVIRT_STORAGE_POOL $VOL_NAME)
     # Pre-touch the VM to set +C, as it can only be set on empty files.
     sudo touch "$volume_path"
@@ -72,7 +73,7 @@ if ! virsh list --all | grep -q $NAME; then
     $TOP_DIR/scripts/configure-vm.py \
         --bootdev network --name $NAME --image "$volume_path" \
         --arch $ARCH --cpus $CPU --memory $MEM --libvirt-nic-driver $LIBVIRT_NIC_DRIVER \
-        --emulator $EMULATOR --network $BRIDGE $VM_LOGGING >&2
+        --emulator $EMULATOR --network $BRIDGE --disk-format $DISK_FORMAT $VM_LOGGING >&2
 
     # Createa Virtual BMC for the node if IPMI is used
     if [[ $(type -P vbmc) != "" ]]; then
diff --git a/devstack/tools/ironic/templates/vm.xml b/devstack/tools/ironic/templates/vm.xml
index 0131e15929..cbfa391927 100644
--- a/devstack/tools/ironic/templates/vm.xml
+++ b/devstack/tools/ironic/templates/vm.xml
@@ -20,7 +20,7 @@
   <devices>
     <emulator>%(emulator)s</emulator>
     <disk type='file' device='disk'>
-      <driver name='qemu' type='qcow2' cache='writeback'/>
+      <driver name='qemu' type='%(disk_format)s' cache='writeback'/>
       <source file='%(imagefile)s'/>
       <target dev='vda' bus='virtio'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>