[Qemu-devel] Qemu limited to 11GB

[Qemu-devel] Qemu limited to 11GB

[Dag Wieers]

Hi,

When I try to use a 80GB disk with qemu, the BIOS (and underlying os) 
reports it as a 10GB disk. I've tried providing the CHS values using 
-hdachs, but it does not work either.

	qemu -hdachs "155061,16,63" -hda /dev/hda

Is qemu limited to < 11GB disks, is there a bug or am I doing something 
wrong ? :)

The disk is said to be 10786 MB by the qemu BIOS, while in reality 
Linux reports: 80026 MB. Linux reports CHS=65535/16/63, while fdisk 
reports: 155061,16,63

It would be useful to have the qemu BIOS print out the CHS it is using.

Kind regards,
--   dag wieers,  dag@wieers.com,  http://dag.wieers.com/   --
[all I want is a warm bed and a kind word and unlimited power]

Re: [Qemu-devel] Qemu limited to 11GB

[Herbert Poetzl]

On Sat, Dec 04, 2004 at 12:32:42PM +0100, Dag Wieers wrote:
> Hi,
> 
> When I try to use a 80GB disk with qemu, the BIOS (and underlying os) 
> reports it as a 10GB disk. I've tried providing the CHS values using 
> -hdachs, but it does not work either.
> 
> 	qemu -hdachs "155061,16,63" -hda /dev/hda

115061 % 65536 = 23989

23989*16*63*512/1024^3 = 11

try using 255/256 heads instead of the 16 heads ...


http://www.allensmith.net/Storage/HDDlimit/Address.htm

                       BIOS    IDE Limit 
---------------------------------------- 
 Maximum Cylinders     1024  65536  1024
 Maximum Heads          256     16    16
 Max. Sectors/track      63    256    63


HTH,
Herbert

> Is qemu limited to < 11GB disks, is there a bug or am I doing something 
> wrong ? :)
> 
> The disk is said to be 10786 MB by the qemu BIOS, while in reality 
> Linux reports: 80026 MB. Linux reports CHS=65535/16/63, while fdisk 
> reports: 155061,16,63
> 
> It would be useful to have the qemu BIOS print out the CHS it is using.
> 
> Kind regards,
> --   dag wieers,  dag@wieers.com,  http://dag.wieers.com/   --
> [all I want is a warm bed and a kind word and unlimited power]
> 
> 
> _______________________________________________
> Qemu-devel mailing list
> Qemu-devel@nongnu.org
> http://lists.nongnu.org/mailman/listinfo/qemu-devel

Re: [Qemu-devel] Qemu limited to 11GB

[Dag Wieers]

On Sat, 4 Dec 2004, Herbert Poetzl wrote:

> On Sat, Dec 04, 2004 at 12:32:42PM +0100, Dag Wieers wrote:
> > Hi,
> > 
> > When I try to use a 80GB disk with qemu, the BIOS (and underlying os) 
> > reports it as a 10GB disk. I've tried providing the CHS values using 
> > -hdachs, but it does not work either.
> > 
> > 	qemu -hdachs "155061,16,63" -hda /dev/hda
> 
> 115061 % 65536 = 23989
> 
> 23989*16*63*512/1024^3 = 11
> 
> try using 255/256 heads instead of the 16 heads ...

No use, I already tried that. It really seems to me that there's a limit 
in qemu.

--   dag wieers,  dag@wieers.com,  http://dag.wieers.com/   --
[all I want is a warm bed and a kind word and unlimited power]

Re: [Qemu-devel] Qemu limited to 11GB

[Fabrice Bellard]

You should use the CVS version and read its documentation about the 
'-hdachs' option. '-hdachs' gives the physical HDD geometry which is has 
the following maximum parameters: 16383,16,63. You can also try to force 
the use of the LBA translation.

Fabrice.

Dag Wieers wrote:
> On Sat, 4 Dec 2004, Herbert Poetzl wrote:
> 
> 
>>On Sat, Dec 04, 2004 at 12:32:42PM +0100, Dag Wieers wrote:
>>
>>>Hi,
>>>
>>>When I try to use a 80GB disk with qemu, the BIOS (and underlying os) 
>>>reports it as a 10GB disk. I've tried providing the CHS values using 
>>>-hdachs, but it does not work either.
>>>
>>>	qemu -hdachs "155061,16,63" -hda /dev/hda
>>
>>115061 % 65536 = 23989
>>
>>23989*16*63*512/1024^3 = 11
>>
>>try using 255/256 heads instead of the 16 heads ...
> 
> 
> No use, I already tried that. It really seems to me that there's a limit 
> in qemu.
> 
> --   dag wieers,  dag@wieers.com,  http://dag.wieers.com/   --
> [all I want is a warm bed and a kind word and unlimited power]
> 
> 
> _______________________________________________
> Qemu-devel mailing list
> Qemu-devel@nongnu.org
> http://lists.nongnu.org/mailman/listinfo/qemu-devel
> 
> 
>