title: Understanding Hard Disk Sector Size
body: <p>I'm currently developing a kernel mode driver that interacts with raw disk operations.</p>
  
  <p>I wish to understand more about the concept of Sector Size.
  Is a sector size a constant value per physical drive that was set when the HDD was manufactured ?</p>
  
  <p>Or is it defined by the file system that is formatted on the Disk ? If so can they be 2 Sector Size ? One for the physical disk and one for the File System ?</p>
  
  <p>I know for example that NTFS has in its BIOS Parameter Block a DWORD called "sector size", is this the NTFS FS sector size ? Or is it the Physical HDD sector size ?</p>
  
  <p>Thanks a lot
  Michael</p>