Getting the cluster size of a hard drive

方法一

https://stackoverflow.com/questions/11373603/determining-volume-cluster-size-without-using-getdiskfreespace

BOOL WINAPI GetDiskFreeSpace(
  __in   LPCTSTR lpRootPathName,
  __out  LPDWORD lpSectorsPerCluster, // <--
  __out  LPDWORD lpBytesPerSector, // <--
  __out  LPDWORD lpNumberOfFreeClusters,
  __out  LPDWORD lpTotalNumberOfClusters
);

方法二

IOCTL