linux device driver
 

Hi,
why/How to know that ide hdd use /dev/hda driver. why it is not use /dev/sda
or other what is the process to know that unknown device will use following driver.

Traditionally IDE devices were named /dev/hdX; and SCSI devices were /dev/sdX.

That changed, I believe, with the 2.6 kernel. IDE devices are now named /dev/sdX.

I am not sure I understand your question.
udev determines how a device will be assigned according to the udev rules. In other words, udev determines weather it is hdc, hda, etc..... Then fstab assigns ownership, permissions, and mount point.

google udev tutorial

Hope this helps.
What do you need the info for anyways?

Also, one way to find the device assignment is
su
fstab -l