macOS How to find out sector size of HD or USB flash drive

G

goyalpk

macrumors newbie

Original poster

• Aug 7, 2009

• #1

Hi there,
How I can I find out sector size of Hard disk or USB flash drive using Cocoa or OS API?
I wanted to use getPreferredBlockSize() method of IOMedia class, but IOMedia is an abstract class.
It is urgent.
Thanks so much in advance.
Pankaj

 

K

kainjow

Moderator emeritus

• Aug 7, 2009

• #2

If you have the /dev/ path to the device, you can use open() to get a file descriptor for it, then ioctl() with DKIOCGETBLOCKSIZE.

 

G

goyalpk

macrumors newbie

Original poster

• Aug 7, 2009

• #3

Thanks a lot for reply. Is there any high level function in Cocoa to do this?
Thanks.
Pankaj

 

G

Guiyon

macrumors 6502a

• Aug 7, 2009

• #4

Another option you have is to use IOKit to enumerate through the kIOBlockStorageDriverClass instances in the IOService tree and grab the kIOMediaPreferredBlockSizeKey property for the ones you want. IIRC, this is the optimal block size of the device not necessarily the logical block size.