Re: Disk geometry from /sys

[Bill Davidsen <davidsen@tmr.com>]

Francis Moreau wrote:
> Hi,
> 
> I'm trying to know the geometry of my hard disk from a bash script
> and that's the reason I'm looking in /sys. The reason is that I'd like
> to figure out the size of a cylinder without doing a
> ioctl(bdev, HDIO_GETGEO, &geo)
> 
> Unfortunately I can't find anything useful and this is certainly a sign
> that I'm doing something wrong.
> 
> Or maybe can I simply assume from my script that the geometry
> is always heads=255 and the number of sectors per track is 63 for all
> disks.
> 
> Looking at parted(8) source code, I  can find this:
> 
> /* The GETGEO ioctl is no longer useful (as of linux 2.6.x).  We could
>  * still use it in 2.4.x, but this is contentious.  Perhaps we should
>  * move to EDD. */
> 
> Could anybody give me some advices ?

Given that the connection between any modern disk geometry and the 
assumption of a fixed number of sectors per track is pretty tenuous, I'm 
not sure any of the sizes, BIOS, boot program, or OS, are more than 
convention anymore.

-- 
Bill Davidsen <davidsen@tmr.com>
   "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot