Subj : IORB_GEOMETRY, PDSK_GETPHYSDEVICEPARAMS and 32 bit sizes
To   : Vitus Jensen
From : David Noon
Date : Sun Nov 16 2003 07:49 pm

Hi Vitus,

Replying to a message of Vitus Jensen to All:

VJ> Looking at OS2DASD.DMD source this shouldn't be a problem but when
VJ> this information is passed to LVM I find only the IOCtl
VJ> PDSK_GETPHYSDEVICEPARAMS.  This IOCtl uses a 16 bit value for Number
VJ> of Cylinders...

That's correct. Remember that that particular IOCtl dates back to the days of
MS-OS/2, so it is wall-to-wall 16-bit, even though the underlying code is
nowadays 32-bit.

VJ> Is my analysis correct?  There is no other IOCtl, Cylinders have to be
VJ> less than 65536?

Look at the OEMHLP_QUERYDISKINFO IOCtl, documented in ADDENDUM.INF. This
allocates a DWORD for cylinder count in its data packet, thus allowing over 4
billion cylinders. Just be aware that the information for this query is cached
from a BIOS interrupt before the kernel switches to protected mode. This means
that you will need a fairly recent BIOS (and SCSI BIOS, if your array is on
SCSI disks) to allow the system to collect the data.

Regards

Dave
<Team PL/I>

--- FleetStreet 1.25.1
* Origin: My other computer is an IBM S/390 (2:257/609.5)

You are viewing proxied material from cvs.synchro.net. The copyright of proxied material belongs to its original authors. Any comments or complaints in relation to proxied material should be directed to the original authors of the content concerned. Please see the disclaimer for more details.