diff --git a/start b/start
index 10ecdb9..ef36dde 100755
--- a/start
+++ b/start
@@ -55,33 +55,46 @@ base_path=base
 default_path=default
 hardware_path=hardware
 specific_path="$VMNAME"
+
+o_base_path="$(mktemp)"
+o_default_path="$(mktemp)"
+o_hardware_path="$(mktemp)"
+o_specific_path="$(mktemp)"
 if [[ -e "$base_path.conf.tmpl" ]]; then
     (
         # shellcheck disable=SC1090
         [[ -e "$base_path.sh" ]] && source "$base_path.sh"
-        envsubst < "$base_path.conf.tmpl" > "$base_path.conf"
+        envsubst < "$base_path.conf.tmpl" > "$o_base_path"
     )
+else
+    cp "$base_path.conf" "$o_base_path"
 fi
 if [[ -e "$default_path.conf.tmpl" ]]; then
     (
         # shellcheck disable=SC1090
         [[ -e "$default_path.sh" ]] && source "$default_path.sh"
-        envsubst < "$default_path.conf.tmpl" > "$default_path.conf"
+        envsubst < "$default_path.conf.tmpl" > "$o_default_path"
     )
+else
+    cp "$default_path.conf" "$o_default_path"
 fi
 if [[ -e "$hardware_path.conf.tmpl" ]]; then
     (
         # shellcheck disable=SC1090
         [[ -e "$hardware_path.sh" ]] && source "$hardware_path.sh"
-        envsubst < "$hardware_path.conf.tmpl" > "$hardware_path.conf"
+        envsubst < "$hardware_path.conf.tmpl" > "$o_hardware_path"
     )
+else
+    cp "$hardware_path.conf" "$o_hardware_path"
 fi
 if [[ -e "$specific_path.conf.tmpl" ]]; then
     (
         # shellcheck disable=SC1090
         [[ -e "$specific_path.sh" ]] && source "$specific_path.sh"
-        envsubst < "$specific_path.conf.tmpl" > "$specific_path.conf"
+        envsubst < "$specific_path.conf.tmpl" > "$o_specific_path"
     )
+else
+    cp "$specific_path.conf" "$o_specific_path"
 fi
 
 if [[ -e "pre-start.sh" ]]; then
@@ -98,10 +111,10 @@ default_arguments=()
 hardware_arguments=()
 specific_arguments=()
 # mask EOF
-read -ra base_arguments -d '' < "$base_path.conf" || true
-read -ra default_arguments -d '' < "$default_path.conf" || true
-read -ra hardware_arguments -d '' < "$hardware_path.conf" || true
-read -ra specific_arguments -d '' < "$specific_path.conf" || true
+read -ra base_arguments -d '' < "$o_base_path" || true
+read -ra default_arguments -d '' < "$o_default_path" || true
+read -ra hardware_arguments -d '' < "$o_hardware_path" || true
+read -ra specific_arguments -d '' < "$o_specific_path" || true
 $DEBUG $SUDO nice --adjustment=-20 taskset --cpu-list '1-5,7-11' \
     qemu-system-x86_64 \
     -name "$VMNAME,process=VMNAME" \