Messages in this thread | | | From | "Khimenko Victor" <> | Date | Wed, 19 Jan 2000 05:49:37 +0300 (MSK) | Subject | Re: IDE drives with > 65535 cylinders |
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In <14469.1277.729609.506341@acronym.anu.edu.au> Tim Potter (Tim.Potter@anu.edu.au) wrote: > Hello. I've got a couple of IBM 35.7 GB DeskStar IDE drives which > seem to confuse Linux and fdisk as they report >65535 cylinders when > probed.
> hde: IBM-DPTA-353750, 35772MB w/1961kB Cache, CHS=72680/16/63 > hdf: IBM-DPTA-353750, 35772MB w/1961kB Cache, CHS=72680/16/63 > hdg: IBM-DPTA-353750, 35772MB w/1961kB Cache, CHS=72680/16/63
> Now fdisk gets really confused as the HDIO_GETGEO ioctl returns > (unsigned short)drive->bios_cyl which is equal to 72680 % 65535 = 7145 > cylinders. This is about 10% of the actual drive capacity.
> It's possible to use the fdisk expert menu to fool around with the CHS > settings and create a usable partition, but afterwards fdisk *still* > gets things wrong with respect to the actual number of cylinders on > the drive although by a slightly different margin - 8191.
> Is there any reason why there is a 32-bit limit on the number of > cylinders apart from the ATAPI spec? (-: It would be nice to have > Linux support these drives straight off.
-- cut -- struct hd_geometry { unsigned char heads; unsigned char sectors; unsigned short cylinders; unsigned long start; }; -- cut --
Looks like someone should carefully track and fix all places where short is used for number of cylinders (all IDE, SCSI, etc drivers, [cs]fdsik and so on). Do you volunteer ?
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