Re: [gentoo-user] Cannot open root device "sda3" or unknown-block (0,0)

[Dale]

Joseph wrote:
> On 11/16/10 21:45, Dale wrote:
>
> [snip]
>>> The BIOS sees both HD but, boot sector is working OK as grub comes up
>>> but then I get a message:
>>>
>>> VFS: Cannot open root device "sda3" or unknown-block (0,0)
>>> please append a correct "root=" boot option; here are the available
>>> partitions:
>>> 0300  4191302 hda driver: ide-cdrom
>>>
>>> So it seems kernel does not see the sata drives, but how it is
>>> possible? Boot partition is on sda
>>>
>>> Someone suggested that BIOS is seeing different logical layout of
>>> cylinders/ heads.
>>> In BIOS setup there a choice of IDE mode, AHCI mode, etc
>>
>> It sounds to me like you don't have the drivers for the chipset.  If you
>> leave those out or they are modules, it can't see the drives.
>>
>> Keep in mind, just because grub sees the drives does not mean the kernel
>> does.  They are two separate things.  Grub only passes info on to the
>> kernel.  Once you select what you want to boot, grub is out of the
>> picture.
>>
>> Dale
>>
>> :-)  :-)
>
> Thanks for the hint.
> What should I look for? I think "lspci" list some chipset, MCP51 but
> kernel is not listing anything on MCP51
>

Try lspci -k from the CD.  That should tell you what driver the CD is 
using.  Then while in the kernel config, just look for that driver.  If 
in menuconfig, try the question mark key.  Then type in the name of the 
driver and it should show you where it is exactly.

Most CDs use the old IDE drivers so you may have to try this site:

http://kmuto.jp/debian/hcl/

That should list all the drivers you need for your hardware.  Details on 
the site as to what to post there.  Neat site too.

Dale

:-)  :-)