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[Solved] Error restored snapshot vm

PostPosted: 24. Apr 2019, 11:45
by range
Hi gues! I use VirtualBox and Virtual Box API Microsoft Com C++ for my project.
It’s VirtualBox 6.0.6 Software Developer Kit (SDK) and VirtualBox 6.0.6 platform packages .
I have a problem. I want to recover a snapshot system, that was created early, but the program shows errors.
My code with comments:

Code: Select all   Expand viewCollapse view

IVirtualBoxClient *virtualBoxClient = nullptr;
IVirtualBox *virtualBox = nullptr;
IMachine *machine = nullptr;
ISession *session = nullptr;
IProgress *progress = nullptr;
ISnapshot* snapshot = nullptr;

BSTR sessiontype = SysAllocString(L"gui");
BSTR machineName = SysAllocString(L"Win7x64");

HRESULT rc = CoCreateInstance(CLSID_VirtualBoxClient, NULL, CLSCTX_INPROC_SERVER, IID_IVirtualBoxClient, (void**)&virtualBoxClient);

rc = virtualBoxClient->get_VirtualBox(&virtualBox);

// looking for a machine with a name Win7x64
rc = virtualBox->FindMachine(machineName, &machine);

// create a session object
rc = CoCreateInstance(CLSID_Session, NULL, CLSCTX_INPROC_SERVER, IID_ISession, (void**)&session);
if (!SUCCEEDED(rc))
printf("Error creating Session instance! rc = 0x%x\n", rc);

// block the machine
machine->LockMachine(session, LockType::LockType_Shared);

// the name of the snapshot system
BSTR snapshotUUID = SysAllocString(L"Win7_test_snapshot");
// looking for a snapshot system
rc = machine->FindSnapshot(snapshotUUID, &snapshot);
// recover snapshot. ERROR: variable rc - E_NOTIMPL Not implemented.
rc = machine->RestoreSnapshot(snapshot, &progress);

printf("Starting VM, please wait ...\n");
//waiting for the end of the operation. Abnormal termination- progress == nullptr !
rc = progress->WaitForCompletion(-1);
// unlocking the machine
rc = session->UnlockMachine();
if (!SUCCEEDED(rc))
printf("Error restore state machine!\n");

Can you help me, how to fix call method error “ RestoreSnapshot - E_NOTIMPL Not implemented” or how to restore a snapshot of the system correctly? Thank you.

Re: Error restored snapshot vm

PostPosted: 24. Apr 2019, 16:13
by mpack
You don't seem to be testing the return value of FindSnapshot()?

Re: Error restored snapshot vm

PostPosted: 24. Apr 2019, 17:03
by range
mpack wrote:You don't seem to be testing the return value of FindSnapshot()?

Return value of FindSnapshot() is S_OK :(

Re: Error restored snapshot vm

PostPosted: 25. Apr 2019, 20:24
by range
Application build order:
1) Compiling VirtualBox.idl and getting dlldata.c, VirtualBox_h.h, VirtualBox_i.c, VirtualBox_p.c files to a console project
2) Creating a source code file in a console project
3) Compiling and running a console project.
Is that right?
Just in case - Visual Studio 2017 project:

Re: Error restored snapshot vm

PostPosted: 25. Apr 2019, 22:40
by range
I created a simple C # application, and got the exact same error there. What's the matter? This is mistake API ? I even changed the OS (virtual) many times.
Code: Select all   Expand viewCollapse view
static void Main(string[] args)
            VirtualBox.VirtualBox virtualBox = new VirtualBox.VirtualBox();
            IMachine vmMachine = virtualBox.FindMachine("Win7x64VB");
            Session session = new Session();
            vmMachine.LockMachine(session, LockType.LockType_Shared);
            IConsole console = session.Console;

            // Restore snapshot
            ISnapshot snapShot = vmMachine.FindSnapshot("Win7_snapshot1");

            IProgress snapShotProgress = vmMachine.RestoreSnapshot(snapShot);

            // unlock before launch VMProcess

            IProgress launchVmProgess = vmMachine.LaunchVMProcess(session, "gui", "None");


Screenshot exception:

Re: Error restored snapshot vm

PostPosted: 1. May 2019, 19:34
by range
Hi gyes!
I found a solution of the problem. Snapshot should be restored with the system that is current for the session. So code will be as follows:

Code: Select all   Expand viewCollapse view
HRESULT rc = machine->LockMachine(session, LockType::LockType_Shared);
rc = machine->FindSnapshot(snapshotUUID, &snapshot);
IMachine* currentMachine(nullptr);
rc = session->get_Machine(&currentMachine);
rc = currentMachine->RestoreSnapshot(snapshot, &progress);
rc = progress->WaitForCompletion(300000);
rc = session->UnlockMachine();

It works with this code.

Re: Error restored snapshot vm

PostPosted: 1. May 2019, 21:38
by socratis
Thank you for the feedback and the solution! 8)
I hope someone finds it useful in the future. Marking as [Solved].