Re: [Qemu-devel] qemu-img documentation

[Panagiotis Issaris <panagiotis.issaris@mech.kuleuven.ac.be>]

Hi,

Jason Brittain wrote:

> ML wrote:
>
>> ---
>> Fabrice Bellard said the following on 11/16/2004 02:46 AM:
>>
>>> Try my last fix. The important fix is in 
>>> hw/ide.c:ide_guess_geometry(). I think the problem is that after 
>>> reboot when installing ide_guess_geometry() returns an invalid 
>>> geometry because the BIOS translated geometry is stored in the MBR 
>>> instead of the real hard disk geometry.
>>>
>>> For the desperate user, I added an option to manually specify the 
>>> BIOS translation mode.
>>
>>
>> With this fix now I can boot XP images newly created with 0.6.1 but I 
>> can't boot any longer my older images created with versions < 0.6.1 
>> unless I specify hda geometry on the command line.
>
>
> This is going to cause lots of people to not be able to figure out
> how to use qemu anymore after an upgrade.  For example, even if I
> knew that I needed to use the -hdachs option (pronounced "headaches"),
> how would I know what geometry numbers to give it?  I'm not real
> good with this sort of thing, and I haven't found any docs yet that
> try to explain it from the perspective of a VM user.  I know, I know,
> you can't have everything.  But, I do think this will cause users
> repeated hdachs.  :)
>
I've used "fdisk c.img" and used the reported values as parameters
for hdachs. This together with specifying the bios translating mode
enabled me to boot old qemu images again.

So, I used:
"fdisk c.img"

Used the p command to print the partition table, which also
shows the necessary disk information:
16 heads, 63 sectors/track, 4161cylinders

And started qemu:
"qemu -hda c.img -hdachs 4161,16,63,none"

Worked for me, but I don't know if fdisk is always
right.

With friendly regards,
Takis

-- 
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Panagiotis Issaris
Katholieke Universiteit Leuven
Division Production Engineering,
Machine Design and Automation
Celestijnenlaan 300B              panagiotis.issaris@mech.kuleuven.ac.be
B-3001 Leuven Belgium                 http://www.mech.kuleuven.ac.be/pma
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