   WiFi.mode(WIFI_OFF);
   Serial.println("\n\nFS test\n");
 
-  if (!mount(SPIFFS, "/")) {
-    fail("mount failed");
+  if (!SPIFFS.begin()) {
+    fail("SPIFFS init failed");
   }
 
   String text = "write test";

#include <ESP8266WiFi.h>
#include "FS.h"

void fail(const char* msg) {
  Serial.println(msg);

  {
    Dir root = SPIFFS.openDir("/");
    while (root.next()) {
        String fileName = root.fileName();
        File f = root.openFile("r");
        Serial.printf("%s: %d\r\n", fileName.c_str(), f.size());
    }
  }

  {
    Dir root = SPIFFS.openDir("/");
    while(root.next()) {
      String fileName = root.fileName();
      Serial.print("deleting ");
      Serial.println(fileName);
      if (!SPIFFS.remove(fileName)) {
        fail("remove failed");
      }
    }
  }

  {
    File tmp = SPIFFS.open("/tmp1.txt", "w");
    tmp.println("rename test");
  }

  {
    if (!SPIFFS.rename("/tmp1.txt", "/tmp2.txt")) {
      fail("rename failed");
    }
    File tmp2 = SPIFFS.open("/tmp2.txt", "r");
    if (!tmp2) {
      fail("open tmp2 failed");
    }
  }

  Serial.println("success");
}
