Processing the data

If you want to work with the data in a more object-oriented way then you probably need to create a SMART class but a SMART struct also works well. For example, a struct that holds values for the most important failure indicators would be:

public struct SMARTAttribute
     {
         public int status;
         public int value;
         public int rawvalue;
         public SMARTAttribute()
         {
             status = 0;
             value = 0;
             rawvalue = 0;
         }
     }
public struct SMART
{
 public SMARTAttribute    RawReadErrorRate;
 public SMARTAttribute    ReallocatedSectorCount;
 public SMARTAttribute    ReallocationEventCount;
 public SMARTAttribute    CurrentPendingSectorCount;
 public SMARTAttribute
                OfflineScanUncorrectableSectorCount;
}

Packing the data into the struct is just a matter of detecting which attribute the current 12 bytes of data represents and the best way to do this is with a switch:

SMART smartdata =new SMART();
foreach (ManagementObject FailData2 in
              FailDataSet)
{
 Byte[] data2 = (Byte[])FailData2.
     Properties["VendorSpecific"].Value;
 for (int i = 0; i < data2[0] - 1; i++)
 {
  int start=i*12;
  switch(data2[start+2])
  {
  case 1:
   smartdata.RawReadErrorRate.value =
                data2[start + 5];
   smartdata.RawReadErrorRate.rawvalue=
      data2[start+7]+256*data2[start+8];
  break;
  case 5:
   smartdata.ReallocatedSectorCount.
       value =data2[start + 5];
   smartdata.ReallocatedSectorCount.
       rawvalue = data2[start + 7] 
             + 256 * data2[start + 8];
   break;
  case 196:
   smartdata.ReallocationEventCount.
       value =data2[start + 5];
   smartdata.ReallocationEventCount.
       rawvalue =data2[start + 7] 
           + 256 * data2[start + 8];
   break;
  case 197:
   smartdata.CurrentPendingSectorCount.
       value = data2[start + 5];
   smartdata.CurrentPendingSectorCount.
       rawvalue = data2[start + 7]
           + 256 * data2[start + 8];
   break;
  case 198:
   smartdata.
     OfflineScanUncorrectableSectorCount.
      value = data2[start + 5];
   smartdata.
     OfflineScanUncorrectableSectorCount.
      rawvalue = data2[start + 7] 
            + 256 * data2[start + 8];
   break;
 }
}

You can add extra code to initialise the other data values and retrieve other attributes if you need them. Once you have seen how it’s done it’s not so difficult.

It is also possible to run such WMI queries remotely once you have worked out how to set the system up to allow it. See Getting remote DCOM (WMI) to work.