Re: [Qemu-devel] "A disk read error occurred"

["Alexander (Sasha) Sirotkin" <sasha.sirotkin@gmail.com>]

On Wed, Jul 2, 2008 at 5:34 PM, Jamie Lokier <jamie@shareable.org> wrote:
> Alexander (Sasha) Sirotkin wrote:
>> On Tue, Jul 1, 2008 at 2:05 AM, Jamie Lokier <jamie@shareable.org> wrote:
>> > Avi Kivity wrote:
>> >> Alexander (Sasha) Sirotkin wrote:
>> >> >For some reason when I try to boot qemu with -hda /dev/sda (or -hda
>> >> >/dev/hda), i.e. to use the whole disk, it fails with the above error
>> >> >"A disk read error occurred". This happens only on IBM/Lenovo laptops
>> >> >(tried a few models), while it works just fine on any desktop I can
>> >> >get my hands on. Probably has something to do with bios...
>> >> >
>> >> >
>> >>
>> >> Can you add some printfs displaying the sector numbers being read?  Some
>> >> disks have trouble accessing the last sector.
>> There are no printfs, no sector numbers, nothing. Just the above error.
>> >>
>> >> Also, an strace can help show the problem.
>> The whole strace is too big, attaching last 1000 lines
>> >
>> > Also, sometimes when booting the BIOS can print a disk read error
>> > message, and an appropriate -hdachs will fix it.  I found that out
>> > when rebooting Windows 2000 after installing it from CD (both in
>> > QEMU), on a virtual disk 1GB in size.
>> >
>>
>> I must say that I don't understand what chs values I should give to
>> qemu. hdparm  shows 9729/255/63, but fdisk insists on 10337,240,63.
>> Both versions do not work with qemu, it says "invalid physical CHS
>> format"
>> BTW, hdparm -i shows yet another version - RawCHS=16383/16/63
>
> Try -hdachs 1023,16,63,lba.
> If that doesn't work, try it without lba.
> If those don't work, try 255 for the middle number, with/without lba.
>

According to the DiskEXplorer for NTFS the correct heads number is
240, however qemu does not allow to set it. Any idea why ? Can I just
remove this limitation in the source code ?

> -- Jamie
>
>
>