diff --git a/etc/tempest.conf.sample b/etc/tempest.conf.sample
index 761a077..fe383bc 100644
--- a/etc/tempest.conf.sample
+++ b/etc/tempest.conf.sample
@@ -193,7 +193,7 @@
 # admin credentials are known. (boolean value)
 #allow_tenant_isolation=false
 
-# Valid secondary image reference to be used in tests. (string
+# Valid primary image reference to be used in tests. (string
 # value)
 #image_ref={$IMAGE_ID}
 
@@ -940,6 +940,10 @@
 # value)
 #disk_format=raw
 
+# Default size in GB for volumes created by volumes tests
+# (integer value)
+#volume_size=1
+
 
 [volume-feature-enabled]