如何在C ++中将驱动器号转换为物理驱动器名称？

Question

My question is this: Given an offline disk connected to my windows machine, how can I get it's volume letter?

The scenario: I need to create a handler to a shared storage (with CreateFile function) in order to use it in the DeviceIoControl function (need to perform SCSI reservations).

The "CreateFile" function gets the physical drive name (ie \\.\\PhysicalDisk1) or the volume letter of the disk (ie \\.\\E:).

My problem is, that I don't want to use the physical drive name, just the disk letter. This works fine when the disk is online, but I have to support also when the disk is offline.

Is there a way to determine the letter when the device/disk is offline? I assume there is, because when I get the disk online, windows automatically gives it the right letter. So if the operation system knows what will be the letter, there must be an API or a tool that I can use too.

Thanks, Daniel.

Answer 1

Unfortunately, when a drive is offline the drive letter is available for use by another drive that may be inserted. So although Windows remembers what drive letter a particular drive used to have, and it attempts to re-use the same letter when it is re-inserted, if another drive was inserted that used the remembered letter then the old drive will get a different letter if it is then inserted.

But you cannot open a Physical Drive, either by name or letter, if that drive is not currently connected. You'll simply get the equivalent of "File not found".