my %data;
# By record:
$data{'Drive C'} = {
   'Used Space OID' => '1.2.3.4.5.1',
   'Size OID' => '1.2.3.4.6.1',
   'Max Size' => 200000,
   'Alocation Units' => 4096,
};

# By field
$data{'Drive C'}{'Used Space OID'} = '1.2.3.4.5.1';
$data{'Drive C'}{'Size OID'} = '1.2.3.4.6.1';
$data{'Drive C'}{'Max Size'} = 200000;
$data{'Drive C'}{'Alocation Units'} = 4096;