diff --git a/lib/nova_plugins/functions-libvirt b/lib/nova_plugins/functions-libvirt
index 045fc8b..dae55c6 100644
--- a/lib/nova_plugins/functions-libvirt
+++ b/lib/nova_plugins/functions-libvirt
@@ -8,7 +8,7 @@
 # ``STACK_USER`` has to be defined
 
 # Save trace setting
-LV_XTRACE=$(set +o | grep xtrace)
+_XTRACE_NOVA_FN_LIBVIRT=$(set +o | grep xtrace)
 set +o xtrace
 
 # Defaults
@@ -134,7 +134,7 @@
 
 
 # Restore xtrace
-$LV_XTRACE
+$_XTRACE_NOVA_FN_LIBVIRT
 
 # Local variables:
 # mode: shell-script
diff --git a/lib/nova_plugins/hypervisor-fake b/lib/nova_plugins/hypervisor-fake
index 3180d91..2434dce 100644
--- a/lib/nova_plugins/hypervisor-fake
+++ b/lib/nova_plugins/hypervisor-fake
@@ -17,7 +17,7 @@
 # cleanup_nova_hypervisor - remove transient data and cache
 
 # Save trace setting
-MY_XTRACE=$(set +o | grep xtrace)
+_XTRACE_VIRTFAKE=$(set +o | grep xtrace)
 set +o xtrace
 
 
@@ -72,7 +72,7 @@
 
 
 # Restore xtrace
-$MY_XTRACE
+$_XTRACE_VIRTFAKE
 
 # Local variables:
 # mode: shell-script
diff --git a/lib/nova_plugins/hypervisor-ironic b/lib/nova_plugins/hypervisor-ironic
index b9e286d..c6ed85d 100644
--- a/lib/nova_plugins/hypervisor-ironic
+++ b/lib/nova_plugins/hypervisor-ironic
@@ -17,7 +17,7 @@
 # cleanup_nova_hypervisor - remove transient data and cache
 
 # Save trace setting
-MY_XTRACE=$(set +o | grep xtrace)
+_XTRACE_HYP_IRONIC=$(set +o | grep xtrace)
 set +o xtrace
 
 source $TOP_DIR/lib/nova_plugins/functions-libvirt
@@ -81,7 +81,7 @@
 
 
 # Restore xtrace
-$MY_XTRACE
+$_XTRACE_HYP_IRONIC
 
 # Local variables:
 # mode: shell-script
diff --git a/lib/nova_plugins/hypervisor-libvirt b/lib/nova_plugins/hypervisor-libvirt
index c54a716..8bbaa21 100644
--- a/lib/nova_plugins/hypervisor-libvirt
+++ b/lib/nova_plugins/hypervisor-libvirt
@@ -17,7 +17,7 @@
 # cleanup_nova_hypervisor - remove transient data and cache
 
 # Save trace setting
-MY_XTRACE=$(set +o | grep xtrace)
+_XTRACE_NOVA_LIBVIRT=$(set +o | grep xtrace)
 set +o xtrace
 
 source $TOP_DIR/lib/nova_plugins/functions-libvirt
@@ -105,7 +105,7 @@
 
 
 # Restore xtrace
-$MY_XTRACE
+$_XTRACE_NOVA_LIBVIRT
 
 # Local variables:
 # mode: shell-script
diff --git a/lib/nova_plugins/hypervisor-openvz b/lib/nova_plugins/hypervisor-openvz
index cce36b8..58ab5c1 100644
--- a/lib/nova_plugins/hypervisor-openvz
+++ b/lib/nova_plugins/hypervisor-openvz
@@ -17,7 +17,7 @@
 # cleanup_nova_hypervisor - remove transient data and cache
 
 # Save trace setting
-MY_XTRACE=$(set +o | grep xtrace)
+_XTRACE_OPENVZ=$(set +o | grep xtrace)
 set +o xtrace
 
 
@@ -62,7 +62,7 @@
 
 
 # Restore xtrace
-$MY_XTRACE
+$_XTRACE_OPENVZ
 
 # Local variables:
 # mode: shell-script
diff --git a/lib/nova_plugins/hypervisor-vsphere b/lib/nova_plugins/hypervisor-vsphere
index 698f836..7c08bc9 100644
--- a/lib/nova_plugins/hypervisor-vsphere
+++ b/lib/nova_plugins/hypervisor-vsphere
@@ -17,7 +17,7 @@
 # cleanup_nova_hypervisor - remove transient data and cache
 
 # Save trace setting
-MY_XTRACE=$(set +o | grep xtrace)
+_XTRACE_NOVA_VSPHERE=$(set +o | grep xtrace)
 set +o xtrace
 
 
@@ -64,7 +64,7 @@
 
 
 # Restore xtrace
-$MY_XTRACE
+$_XTRACE_NOVA_VSPHERE
 
 # Local variables:
 # mode: shell-script
diff --git a/lib/nova_plugins/hypervisor-xenserver b/lib/nova_plugins/hypervisor-xenserver
index e097990..3eb9149 100644
--- a/lib/nova_plugins/hypervisor-xenserver
+++ b/lib/nova_plugins/hypervisor-xenserver
@@ -17,7 +17,7 @@
 # cleanup_nova_hypervisor - remove transient data and cache
 
 # Save trace setting
-MY_XTRACE=$(set +o | grep xtrace)
+_XTRACE_XENSERVER=$(set +o | grep xtrace)
 set +o xtrace
 
 
@@ -111,7 +111,7 @@
 
 
 # Restore xtrace
-$MY_XTRACE
+$_XTRACE_XENSERVER
 
 # Local variables:
 # mode: shell-script