Question

Just trying to pull off some SMART info from connected Hard Drives on any computer my application will run on.

I’m using WMI for a lot of other stuff in the program, and every question about SMART I’ve looked at makes reference to Win32_DiskDrive. However, the data in here is really quite minimal and probably not SMART – I’m searching for information such as ‘Spin Retry Count’. Any ideas?

Answer 1

You are using the wrong class (you want MSStorageDriver_ATAPISmartData).
To change what attribute you want change byte SpinRetryCount = 0x0A; to whatever value you wish (e.g. 0x02 for throughput performance)

[StructLayout(LayoutKind.Sequential)]
        public struct Attribute
        {
            public byte AttributeID;
            public ushort Flags;
            public byte Value;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
            public byte[] VendorData;
        }

        static void getSMARTAttr()
        {
            try
            {
                Attribute AtributeInfo;
                ManagementScope Scope = new ManagementScope(String.Format("\\\\{0}\\root\\WMI", "localhost"), null);
                Scope.Connect();
                ObjectQuery Query = new ObjectQuery("SELECT VendorSpecific FROM MSStorageDriver_ATAPISmartData");
                ManagementObjectSearcher Searcher = new ManagementObjectSearcher(Scope, Query);
                byte SpinRetryCount = 0x0A;
                int Delta = 12;
                foreach (ManagementObject WmiObject in Searcher.Get())
                {
                    byte[] VendorSpecific = (byte[])WmiObject["VendorSpecific"];
                    for (int offset = 2; offset < VendorSpecific.Length; )
                    {
                        if (VendorSpecific[offset] == SpinRetryCount)
                        {

                            IntPtr buffer = IntPtr.Zero;
                            try
                            {
                                buffer = Marshal.AllocHGlobal(Delta);
                                Marshal.Copy(VendorSpecific, offset, buffer, Delta);
                                AtributeInfo = (Attribute)Marshal.PtrToStructure(buffer, typeof(Attribute));
                                Console.WriteLine("AttributeID {0}", AtributeInfo.AttributeID);
                                Console.WriteLine("Flags {0}", AtributeInfo.Flags);
                                Console.WriteLine("Value {0}", AtributeInfo.Value);
                                //if you want HEX values use this line
                                //Console.WriteLine("Value {0}", BitConverter.ToString(AtributeInfo.VendorData));
                                //if you want INT values use this line
                                Console.WriteLine("Data {0}", BitConverter.ToInt32(AtributeInfo.VendorData, 0));
                            }
                            finally
                            {
                                if (buffer != IntPtr.Zero)
                                {
                                    Marshal.FreeHGlobal(buffer);
                                }
                            }
                        }
                        offset += Delta;
                    }
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(String.Format("Exception {0} Trace {1}", e.Message, e.StackTrace));
            }
            Console.WriteLine("Press Enter to exit");
            Console.Read();
        }

And remember that if you get anything other than 0, you need to buy a new hard drive!
Also this code requires UAC elevation, so you need to run the application as an administrator or you will get an exception.