Qual sistema descreve com precisão o tamanho real da unidade?
No Windows, use a classe WMI Win32_DiskDrive:
The Win32_DiskDrive WMI class represents a physical disk drive as seen by a computer running Windows. Like the Win32_LogicalDisk WMI class, it has lots of properties, as listed at http://msdn.microsoft.com/en-us/library/windows/desktop/aa394132(v=vs.85).aspx.
Fonte Obtenção uma lista de unidades lógicas e físicas na linha de comando .
Para recuperar os tamanhos reais, execute o seguinte comando:
wmic diskdrive get caption, size
Exemplo de saída:
> wmic diskdrive get caption, size
Caption Size
WDC WD5000LPVX-08V0TT5 500105249280
SanDisk Cruzer USB Device 64009128960
Seagate Expansion Desk USB Device 3000582144000