CreateVirtualDisk API?

• Tuesday, June 28, 2011 3:35 PM

   

   
  

  0

  Not strictly a Hyper-V question but definitely a virtual one.

  I am battling with the virtual disk API, CreateVirtualDisk() in particular, on Windows 7x64Ultimate using VS2008SP1 and native C++.

  The idea is to use a VSS snapshot as the source for a new disk - I'm trying to duplicate some of the functionality found in the SysInternals Disk2VHD app which lets you sanp from a live, bootable, volume. Please see code below. The VSS snap (wrapped in VSSCopierW7 object) the completes sucessfull. The app is running with elevated privileges- whatever parameters I try (as suggested in the API docs) the error code is always ERROR_INVALID_PARAMETER. What I am actually trying to do is create a dynamic VHD that allocates only as much storage as it needs for my bootable C drive, so it can be mounted in Virtual PC or attached to be a bootable virtual drive.

  Thx++

  Jerry

   P.S.
  

  m_options.drive == "C:\\";

    // destructor handles cleanup of shadow volume
        Chordia::VSSCopier* pCopier = new Chordia::VSSCopierW7(m_options.drive,m_options.drive);
  
        // handles destruction and thus closure of VSS
        std::auto_ptr<Chordia::VSSCopier> copy_ptr(pCopier);
  
        // this handles VSS creation etc
        copy_ptr->Copy();
        // get the fully qualified UNC name for the snapshot
        string_t root = copy_ptr->root_name();
        // set up for VirtDisk calls
        VIRTUAL_STORAGE_TYPE storageType =
        {
          VIRTUAL_STORAGE_TYPE_DEVICE_VHD,
          VIRTUAL_STORAGE_TYPE_VENDOR_MICROSOFT
        };
        
        VIRTUAL_DISK_ACCESS_MASK vdam = (VIRTUAL_DISK_ACCESS_MASK)(VIRTUAL_DISK_ACCESS_CREATE); // |VIRTUAL_DISK_ACCESS_WRITABLE|VIRTUAL_DISK_ACCESS_READ|VIRTUAL_DISK_ACCESS_GET_INFO);
        CREATE_VIRTUAL_DISK_FLAG flags = CREATE_VIRTUAL_DISK_FLAG_FULL_PHYSICAL_ALLOCATION; // CREATE_VIRTUAL_DISK_FLAG_NONE;
        CREATE_VIRTUAL_DISK_PARAMETERS parameters =
        {
          CREATE_VIRTUAL_DISK_VERSION_1
        };
        //
        parameters.Version1.UniqueId = GUID_NULL;
        parameters.Version1.MaximumSize = 0x40000000; // 0
        parameters.Version1.BlockSizeInBytes = CREATE_VIRTUAL_DISK_PARAMETERS_DEFAULT_BLOCK_SIZE;
        parameters.Version1.ParentPath = 0;
        parameters.Version1.SourcePath = root.c_str();
        parameters.Version1.SectorSizeInBytes = CREATE_VIRTUAL_DISK_PARAMETERS_DEFAULT_SECTOR_SIZE;
        // our new disk handle
        HANDLE handle = 0;
        // call
         dwRet = CreateVirtualDisk(&storageType,_T("t:\\test.vhd"),vdam,NULL,flags,0,&parameters,0,&handle);
        // dump debug 
        DBMSG2(_T("CreateVirtualDisk: 0x") << Chordia::toHex(dwRet) << " VSS snapshot: " << root);
        if (dwRet != ERROR_SUCCESS)
        {
          Chordia::CSysError se(dwRet);
          if (dwRet == ERROR_INVALID_PARAMETER)
          {
            int i = 0;
          }
          DBMSG2("Error: " << se.data());
        }

  
  
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