см. Win32 :: DriveInfo
($SectorsPerCluster, $BytesPerSector, $NumberOfFreeClusters,
$TotalNumberOfClusters, $FreeBytesAvailableToCaller, $TotalNumberOfBytes, $TotalNumberOfFreeBytes) = Win32::DriveInfo::DriveSpace( drive );
$SectorsPerCluster - number of sectors per cluster.
$BytesPerSector - number of bytes per sector.
$NumberOfFreeClusters - total number of free clusters on the disk.
$TotalNumberOfClusters - total number of clusters on the disk.
$FreeBytesAvailableToCaller - total number of free bytes on the disk that
are available to the user associated with the
calling thread, b.
$TotalNumberOfBytes - total number of bytes on the disk, b.
$TotalNumberOfFreeBytes - total number of free bytes on the disk, b.