MSDN上说：
Communications Resources
The CreateFile function can create a handle to a communications resource, such
as the serial port COM1. For communications resources, the dwCreationDisposition
parameter must be OPEN_EXISTING, and the hTemplate parameter must be NULL. Read,
write, or read-write access can be specified, and the handle can be opened for
overlapped I/O. For more information about communications, see Communications.
Disk Devices
Windows NT: You can use the CreateFile function to open a disk drive or a partition
on a disk drive.The function returns a handle to the disk device; that handle can be
used with the DeviceIOControl function. The following requirements must be met
in order for such a call to succeed:
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The caller must have administrative privileges for the operation to succeed on a hard
disk drive.The lpFileName string should be of the form //./PHYSICALDRIVEx to open the
hard disk x. Hard disk numbers start at zero. For example:
String Meaning
//./PHYSICALDRIVE2 Obtains a handle to the third physical drive on the user's computer.
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从上面这段来看，//./Scsi0 应该是系统的第一块Scsi硬盘
The lpFileName string should be //./x: to open a floppy drive x or a partition x on a hard
disk. For example:
String Meaning
//./A: Obtains a handle to drive A on the user's computer.
//./C: Obtains a handle to drive C on the user's computer.
