How to change RAM/CPUs of vmware VM using Java?

Question

My team is responsible for dynamically changing settings of vmware VMs using java. I have been tasked with changing the amount of available RAM and number of CPUs assigned to an already created vmware VM which exists on VCenter/VSphere.

How can I change the amount of RAM or number of CPUs for a vmware VM using java? I have been searching all over the net for clues, and havent found much.

Answer 1

Here is the Sample code to change VM RAM and CPU with specified values using vSphere java API.

Input::

1. CPU(numCPUs) - Provide num of cpus count,it never exceeds host supported num of cpus
2. RAM(ramMB) - Provide ram value in MB, it never exceed host max alloted memory.

Note:: For PowerON VM- Before modify RAM/CPU it is mandatory to enable the VM Memory Hot Add & CPU Hot Plug feature and also VM OS supports.

Sample Code ::

  public static void changeVMRAMandCPU(ServiceInstance si, String vmName,
        long ramMB, int numCPUs) {
    String waitStr = null;
    try {
        Folder rootFolder = si.getRootFolder();
        VirtualMachine vm = (VirtualMachine) new InventoryNavigator(
                rootFolder).searchManagedEntity("VirtualMachine", vmName);
        HostSystem hs = new HostSystem(si.getServerConnection(), vm
                .getRuntime().getHost());
        System.out.println("Host Name ::" + hs.getName());
        VirtualMachineConfigSpec vmConfigSpec = new VirtualMachineConfigSpec();
        if (isValidCPUCount(numCPUs, hs)) {
            vmConfigSpec.setNumCPUs(numCPUs);
        } else {
            System.out.println("NotAllowed::Provided cpu count " + numCPUs
                    + " is more then the host --> " + hs.getName()
                    + " cpu count "
                    + hs.getHardware().getCpuInfo().getNumCpuCores());
        }

        if (isValidRam(ramMB, hs)) {
            vmConfigSpec.setMemoryMB(ramMB);
        } else {
            System.out.println("NotAllowed::Provided ram " + ramMB
                    + " is more then the host --> " + hs.getName()
                    + " ram " + hs.getHardware().getMemorySize());
        }
        System.out.println("Before modify VM RAM , CPU ==>"
                + vm.getConfig().getHardware().getMemoryMB() + " MB ,"
                + vm.getConfig().getHardware().getNumCPU() + " CPU,");
        Task task = vm.reconfigVM_Task(vmConfigSpec);
        waitStr = task.waitForTask();
        if (waitStr != null && waitStr.equalsIgnoreCase("success")) {
            vm = (VirtualMachine) new InventoryNavigator(rootFolder)
                    .searchManagedEntity("VirtualMachine", vmName);
            System.out.println("After modify VM RAM , CPU ==>"
                    + vm.getConfig().getHardware().getMemoryMB() + " MB ,"
                    + vm.getConfig().getHardware().getNumCPU() + " CPU,");
        } else {
            System.out.println("Error::VM Reconfig fail...");
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public static boolean isValidCPUCount(int cpu, HostSystem hs) {
    int hostCpusCount = hs.getHardware().getCpuInfo().getNumCpuCores();
    if (cpu <= hostCpusCount) {
        return true;
    }
    return false;
}

public static boolean isValidRam(long ram, HostSystem hs) {
    long hostMem = hs.getHardware().getMemorySize() / (1024L * 1024L);
    if (ram < hostMem) {
        return true;
    }
    return false;
}