diff --git a/devstack-vm-gate.sh b/devstack-vm-gate.sh
index a37679f6..0dd4d730 100755
--- a/devstack-vm-gate.sh
+++ b/devstack-vm-gate.sh
@@ -124,7 +124,6 @@ EOF
         echo "VIRT_DRIVER=ironic" >>localrc
         echo "IRONIC_BAREMETAL_BASIC_OPS=True" >>localrc
         echo "IRONIC_VM_COUNT=3" >>localrc
-        echo "IRONIC_VM_EPHEMERAL_DISK=1" >>localrc
         echo "IRONIC_VM_LOG_DIR=$BASE/$LOCALRC_OLDNEW/ironic-bm-logs" >>localrc
         echo "DEFAULT_INSTANCE_TYPE=baremetal" >>localrc
         if [[ "$DEVSTACK_GATE_IRONIC_BUILD_RAMDISK" -eq 0 ]]; then
@@ -135,6 +134,10 @@ EOF
             echo "IRONIC_ENABLED_DRIVERS=fake,agent_ssh,agent_ipmitool" >>localrc
             echo "IRONIC_BUILD_DEPLOY_RAMDISK=False" >>localrc
             echo "IRONIC_DEPLOY_DRIVER=agent_ssh" >>localrc
+            # agent driver doesn't support ephemeral volumes yet
+            echo "IRONIC_VM_EPHEMERAL_DISK=0" >>localrc
+        else
+            echo "IRONIC_VM_EPHEMERAL_DISK=1" >>localrc
         fi
     fi