How to get hard disk capacity?

[Jecci]

This Disk is not formatted,no initializtion.So can't use GetDiskFreeSpace function.

I use DeviceIoControl function for send IOCTL_DISK_GET_DRIVE_GEOMETRY command to get Disk geometry,but why the returns Cylinders is 36474 ?

I gets my disk geometry:
Cylinders 36474 (LowPart 36474,HighPart 0)
MediaType FixedMedia
TracksPerCylinder 255
SectorsPerTrack 63
BytesPerSector 512

Please help,Thanks in advance.

[WingedPanther]

It's just a guess, but wouldn't you just multiply the numeric results to get 300,008,862,720 bytes?

[Jecci]

Hi,wingedPanther.Thank you for your reply.
Yes,This Hard Drive capacity is 300GB,but I don't known why Per Cylinder is 255 Tracks?what's the definition?

[WingedPanther]

I don't know why it would be 255 Tracks, though I notice it is 256-1 so perhaps a track is "not usable" for redundancy, check bits, or something else.

[Jecci]

Thanks,I see.