Nemurenai has asked for the wisdom of the Perl Monks concerning the following question:

Most revered monks, according to http://www.microsoft.com/whdc/archive/smartdrv.mspx it should be possible to extract SMART drive info by using WMI. However, I can't figure out how exactly to go about it. This is what I've come up with so far: 
use warnings;
use Win32::OLE qw( in );

my $WMIServices;
my $Machine = ".";

$WMIServices = Win32::OLE->GetObject( "winmgmts:{impersonationLevel=
        impersonate,(security)}//".$Machine );

my $res = $WMIServices->ExecQuery("select * from MMStorageDriver_Failu
+rePredictData");

foreach (keys %$res)
{
    print "$_\n";
}

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which outputs 
Count
Security_

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It seems to me that WMI resources tend to have keys in the hash which don't show up in a 'foreach (keys %$foo)' - is this correct? And if so, is there any way to extract these keys? I've been unable to find out which ones WMI provides for SMART info. Thanks

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Re: SMART info from drives in win32 using WMI
by wfsp (Abbot) on May 17, 2006 at 13:36 UTC
    Not an answer to your question but one way of looking at what is returned is to use Data::Dumper

    For me, print Dumper $res; returns: 

    $VAR1 = bless( 
  {
    'Count' => undef,
    'Security_' => bless( 
      {
        'ImpersonationLevel' => 3,
        'AuthenticationLevel' => 6,
        'Privileges' => bless( 
          {
            'Count' => 1
          },
        'Win32::OLE'
        )
      },
    'Win32::OLE'
    )
  },
  'Win32::OLE'
);

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Re: SMART info from drives in win32 using WMI
by McDarren (Abbot) on May 17, 2006 at 13:38 UTC
    I don't know much about WMI resources, but I do know that when dealing with data structures - Data::Dumper::Simple is my very best friend :)

    Adding the following to your code... 

    use Data::Dumper::Simple;
# your code here...
print Dumper($res);

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    ...yields the following result on my Win32 machine... 

    $res = bless( {
                'Count' => undef,
                'Security_' => bless( {
                                        'ImpersonationLevel' => 3,
                                        'AuthenticationLevel' => 6,
                                        'Privileges' => bless( {
                                                                 'Coun
+t' => 1
                                                               }, 'Win
+32::OLE' )

                                      }, 'Win32::OLE' )
              }, 'Win32::OLE' );

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    So I guess the resulting data structure is a little more complex than just a simple hash. No smartdrive info there of course (because I'm not running any), but I suspect that if you try the same thing on your machine you might find the clue that you need.

    Hope this helps,
    Darren :)

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      Thanks for the reply, but Dumper doesn't provide me with anything useful; if I replace the last part of the code with 
      my $DriveCollection = $WMIServices->InstancesOf("Win32_DiskDrive" );
foreach my $Drive ( in( $DriveCollection ) )
{
    print Dumper $Drive;
    print $Drive->{'Status'};
}

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      I get a huge dump of a data structure and then the text 'OK' -the property 'Status' is documented in http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wmisdk/wmi/win32_diskdrive.asp but not hinted at anywhere in the Dumper output. I can't find a corresponding page for querying SMART info, hence my question.
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        Well, again let me point out that I know next to nothing about WMI, so I could be very well just blowing air out my rear-end here. However, looking at that "link" you gave I see the following: 
        For IDE, this polling consists of sending the READ_SMART_STATUS comman
+d. If this status indicates an error, a WMI event will be launched th
+at includes the SMART attribute data.

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        It doesn't actually specify what is returned in the absence of an error. Your reply infers that print $Drive->{'Status'}; produces 'OK' ...could it be that this is the entirety of the status?

        Cheers,
        Darren :)

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