Emulate HDD as SSD and SSD as HDD: Sample API script

Recently I wanted to test vFRC (vSphere Flash Read Cache) feature interop with vSphere DRS and vSphere HA. I was figuring out ways to emulate my hosts local HDDs as SSD as I did not have real SSDs in my lab. There are couple of ways I used to fake/emulate local HDD as SSD earlier but this time I found other cool way to automate this quickly by using readily available API. The API that I am talking about is markAsSSD(). This API got introduced in vSphere 6.0. It is important to know why this API is made officially available. The reason this API primarily introduced is: Some time SSDs behind some controllers might not be recognized as SSD correctly. Other use cases for this API can be used to test VMware vSAN (just playing around), vFRC, flash host cache, interop testing etc. Of course, performance of real SSD is incomparable with fake SSD.

Below is the complete code sample which can help you quickly to Mark the local Lun of the host as SSD..

//:: # Author: Vikas Shitole
//:: # Website: www.vThinkBeyondVM.com
//:: # Product/Feature: vCenter Server/Storage
//:: # Description: Mark the local Lun of the host as SSD for testing purpose.

package com.vmware.yavijava;
import java.net.MalformedURLException;
import java.net.URL;
import com.vmware.vim25.ScsiLun;
import com.vmware.vim25.mo.Folder;
import com.vmware.vim25.mo.HostStorageSystem;
import com.vmware.vim25.mo.HostSystem;
import com.vmware.vim25.mo.InventoryNavigator;
import com.vmware.vim25.mo.ServiceInstance;
import com.vmware.vim25.mo.VirtualMachine;

public class MarkAsSSD {

public static void main(String[] args) throws Exception {
System.out.println("Usage: MarkAsSSD url username password hostip/fqdn");

URL url = null;
url = new URL(args[0]);
} catch ( MalformedURLException urlE)
System.out.println("The URL provided is NOT valid. Please check it.");
String username = args[1]; //vCenter username
String password = args[2]; //vCenter password
String hostname = args[3]; // host IP on which local HDD is available
String LunDisplayName="Local VMware Disk (mpx.vmhba1:C0:T2:L0)"; //Add the Display name of the lun that can be seen from VI client or NGC
// Initialize the system, set up web services
ServiceInstance si = new ServiceInstance(url, username,
password, true);

Folder rootFolder = si.getRootFolder();
HostSystem host = null;

host = (HostSystem) new InventoryNavigator(rootFolder)
.searchManagedEntity("HostSystem", hostname);

if (host == null) {
System.out.println("Host not found on vCenter");

HostStorageSystem hhostsystem = host.getHostStorageSystem();
ScsiLun[] scsilun = hhostsystem.getStorageDeviceInfo().getScsiLun();
boolean flag = false;
for (ScsiLun lun : scsilun) {
System.out.println("Display Name"+lun.getDisplayName());
if (lun.getDisplayName().equals(
LunDisplayName)) {
flag = true;
// hhostsystem.markAsNonSsd_Task(lun.getUuid());


if (flag) {
System.out.println("LUN is marked as SSD successfully");

System.out.println("LUN is NOT marked as SSD, plz check if local lun is in use");




– For the sake of simplicity, I have hard-coded LUN display name, you can change it based on your environment.
– You can scale the same code to mark all the local HDDs to SSDs in all the hosts across datacenter or multiple datacenter.
– I would like you to have your attention on other new useful/handy related vSphere 6.0 APIs such as “MarkAsNonSSD” , “MarkAsLocal”, “MarkAsNonLocal“. Same sample can be leveraged to automate these related APIs.

If you have still not setup your YAVI JAVA Eclipse environment:Getting started tutorial

Important tutorials to start with: Part I & Part II