second hard disk trouble

[Olivier Croissant]

In my case , beginning with a fresh install of Win98 on a 770Z with a 14 gig
HD,
partition magic see the entire disk.

Olivier

> -----Original Message-----
> From: Mark Kennedy [mailto:mark.kennedy@gs.com]
> Sent: Tuesday, June 15, 1999 12:19 PM
> To: linux-thinkpad@www.bm-soft.com
> Subject: Re: second hard disk trouble
>
>
> are you saying you ran partition magic v4.X against a 14G drive, and
> it saw the entire drive?  when i ran it, it only saw 8G.  when i called
> them, they told me it was a BIOS limitation and that they were dependent
> on the BIOS for the geometry.  was i taken?  (you can tell i've
> been living
> off the backs of SA's for too long :-).
>
> /mark
>
> Rob Mayoff wrote:
> >
> > | PIIX4: IDE controller on PCI bus 00 dev 39
> > | PIIX4: not 100% native mode: will probe irqs later
> > |     ide0: BM-DMA at 0xfcf0-0xfcf7, BIOS settings: hda:DMA, hdb:pio
> > |     ide1: BM-DMA at 0xfcf8-0xfcff, BIOS settings: hdc:DMA, hdd:pio
> > | hda: IBM-DYLA-28100, ATA DISK drive
> > | hdc: IBM-DCYA-214000, ATA DISK drive
> > | ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
> > | ide1 at 0x170-0x177,0x376 on irq 15
> > | hda: IBM-DYLA-28100, 7815MB w/459kB Cache, CHS=1058/240/63, UDMA
> > | hdc: IBM-DCYA-214000, 7559MB w/420kB Cache, CHS=16383/15/63, UDMA
> > |
> > | I'm not sure if the CHS values are correct, but the size
> certainly isn't
> > | - its smaller than the 8GB drive on the primary! I'm worried that the
> > | Heads value is so low - this looks more like the actual value rather
> > | than the 'large' value that should maybe be there.
> >
> > None of the CHS numbers mean anything about the actual disk geometry
> > these days.  The drive hides its true geometry.
> >
> > | fdisk (under linux)
> > | seems happy to partition it to 7.5GB, but I didn't write it back. Any
> > | ideas what I'll need to do to fix this?
> >
> > The easiest way by far is simply to use Partition Magic (4.0) to
> > partition the disk.  It sees the actual disk geometry.  The Linux kernel
> > doesn't care about the purported CHS numbers; it pays attention to the
> > partition table.
> >
> > If you want to do it the hard way:
> >
> > WARNING: I haven't tried this.  I used PM.  However, from reading the
> > Large Disk HOWTO and /usr/src/linux/Documentation/ide.txt, I gather that
> > this may work.
> >
> > Run "hdparm -i /dev/hdc" (as root).  Look for LBAsects.  That should be
> > 27609120, which is the actual number of sectors on the disk.  (Each
> > sector is 512 bytes; that works out to 14135869440 bytes = ~14.1GB.)
> >
> > 27609120 sectors / 63 sectors per head = 438240 heads
> > 438240 heads / 240 heads per cylinder = 1826 cylinders
> >
> > So you want your disk geometry to be 1826/240/63.  Add this to the
> > kernel command line:
> >
> >         hdc=1826,240,63
> >
> > One slight problem.  I don't know what will happen if you have the CDROM
> > (DVDROM) drive installed at boot.
> >
> > The 16383/15/63 numbers are reported by the drive to mean "really big".
> > Unfortunately, looking at ide.c in my 2.0.36 kernel, I see that Linux
> > only recognizes 16383/16/63 as "really big". (Note: 15 != 16.) I don't
> > know why the drive reports 16383/15/63 instead. But because of that, and
> > because the actual drive size (LBAsects) is more than 10% larger than
> > the CHS indicates, Linux assumes that LBAsects is wrong and uses the
> > reported CHS.
> >
> > I'll probably play with this a bit more after my next full backup.
>