fix config file examples, houskeeping, etc
diff --git a/configs-examples/hdd.yaml b/configs-examples/hdd.yaml
index dcb5f9e..d38904a 100644
--- a/configs-examples/hdd.yaml
+++ b/configs-examples/hdd.yaml
@@ -1,17 +1,11 @@
+include: default.yaml
+
 explicit_nodes:
     local: testnode
 
-internal:
-    var_dir_root: /tmp/perf_tests
-
-testnode_log_root: /tmp/perf_tests_rem
-
 tests:
     - io:
         cfg: hdd
         params:
-            FILENAME: FILE_ON_USB_HDD
-            NUM_ROUNDS: 7
-
-logging:
-    extra_logs: 1
\ No newline at end of file
+            FILENAME: ${FILEPATH}
+            FILESIZE: ${FILESIZE}