disable vm (#1643)

server/src/assembly/resources/conf/iotdb-engine.properties

@@ -252,7 +252,7 @@ default_fill_interval=-1
 ### Merge Configurations
 ####################
 # Is vm merge enable.
-enable_vm=true
+enable_vm=false
 
 # The max vm num of each memtable. When vm num exceeds this, the vm files will merge to one.
 max_vm_num=10

server/src/main/java/org/apache/iotdb/db/conf/IoTDBConfig.java

@@ -254,7 +254,7 @@ public class IoTDBConfig {
   /**
    * Is vm merge enable
    */
-  private boolean enableVm = true;
+  private boolean enableVm = false;
 
   /**
    * The max vm num of each memtable. When vm num exceeds this, the vm files will merge to one.