# Gentoo on a SATA-only system (with 2.6 kernel)

## airflow

Hi!

After my very positive first experiences with gentoo on my old laptop I decided to switch completely to Gentoo and make it my main-OS also on my workstation (a Dell Dimension 8300 with a SATA-drive, Seagate).

Problem is, the kernel I built in the install-process of Gentoo will not boot. It hangs with the following message:

```

VFS: Cannot open root device "sda3" or unknown-block(0,0)

Please append a correct "root=" boot option

Kernel panic: VFS: Unable to mount root fs on unknown-block(0,0)

```

My grub.conf looks like this

```

title Gentoo

root (hd0,0)

kernel (hd0,0)/bzImage-first root=/dev/sda3

```

The kernel I use is theone from the "development-sources" from Gentoo, which should be the actual vanilla 2.6 kernel.

Other people had similar problems, but their solutions will not work for me. For instance, I tried to change the grub.conf to "root=/dev/hde3" and "root=/dev/hda3", I tried to add "noapic" to the kernel options, I disabled IDE-DMA in the kernel completely.. The problem remains, however. One guy had success by changing some BIOS-settings, but my Dell-BIOS does not have those.

Anyone who has a clue, please give me some input! I don't know what to do anymore.

regards,

airflow

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## xr31Daisy

In your grub config, in root=/dev/sda3, you're selecting an SCSI device, SATA should be like IDE, and it's an 'hdx' device ( mine is hdc ). How did you install Gentoo ? While you were installing, how did you partition the disk ? ( format /dev/??? ) In theory, the device name shouldn't have changed ...

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## airflow

As far as I know, kernel 2.6 sees SATA devices as SCSI devices. This is also reflected in the kernel-configs, where you have to enable SATA support in the SCSI-section.

For installing, I used a Live-CD which used the 2.6 kernel (2.4 did not work), and the disc was reflected as /dev/sda. So this should be right...

regards,

airflow

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## vince

 *airflow wrote:*   

> As far as I know, kernel 2.6 sees SATA devices as SCSI devices. This is also reflected in the kernel-configs, where you have to enable SATA support in the SCSI-section.
> 
> For installing, I used a Live-CD which used the 2.6 kernel (2.4 did not work), and the disc was reflected as /dev/sda. So this should be right...
> 
> regards,
> ...

 

I'm am having the same problem, only i have two SATA drives set up in a raid fashion.  I kept my /boot partition /dev/sda2 unraided and have an identical partition on the second drive /dev/sdb2.  I have my root partions as /dev/sda5 and /dev/sdb5  raided to /dev/md0 and my home is /dev/sda6 and /dev/sdb6 raided to /dev/md1.  I get the exact same error.  I am using the AMD64 liveCD dated 12/21/2003.

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## taskara

what chipset is it?

if it is silicon image sata, then it will still be /dev/hde

but if it is intel, promise or via, it will be /dev/sda

can you post your fdisk printout?  and fstab?

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## airflow

As far as I am concerned, the problem is solved. I use the ICH controller from Intel, and the reason for the troubles was that I believed that generic SCSI support in the kernel combined with enabled SATA-functionality is sufficiant. But it was not, I also had to enable SCSI disk support. AND I had to disable apic via a kernel option in grub (noapic), otherwise it locks up too while booting (but then with another errormessage, to be exact with none). But with the kernel option it works, finally! :)

regards,

airflow

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## taskara

cool  :Smile: 

you may want to try the latest mm-sources, they are terrific.

I run them on my p4 system sata on intel and silicon image controllers.

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## vince

 *airflow wrote:*   

> As far as I am concerned, the problem is solved. I use the ICH controller from Intel, and the reason for the troubles was that I believed that generic SCSI support in the kernel combined with enabled SATA-functionality is sufficiant. But it was not, I also had to enable SCSI disk support. AND I had to disable apic via a kernel option in grub (noapic), otherwise it locks up too while booting (but then with another errormessage, to be exact with none). But with the kernel option it works, finally! 
> 
> regards,
> 
> airflow

 

what does your new grub entry look like.  I added noapic as a option in grub.  But i'm not sure if the syntex was correct.  I added just the word "noapic."

```
default 0

timeout 5

splashimage=(hd0,1)/boot/grub/splash.xpm.gz

title=Gentoo 2.6.1 AMD64

root (hd0,1)

kernel (hd0,1)/boot/bzImage root=/dev/md0 hda=ide-scsi hdc=ide-scsi noapic

title=Windows XP

root (hd0,0)

chainloader (hd0,0)+1
```

Is this the correct way to do it.

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## taskara

apic=off

I think.. but I'm not sure..

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## vince

 *taskara wrote:*   

> apic=off
> 
> I think.. but I'm not sure..

 

will try it.  thanks

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## vince

 *vince wrote:*   

>  *taskara wrote:*   apic=off
> 
> I think.. but I'm not sure.. 
> 
> will try it.  thanks

 

nope no good.

I read in another post about having to have this in the kernel:

```
File systems

 -> Pseudo file systems

 -> /dev file system support (OBSOLETE)   DEVFS_FS

   -> Automatically mount at boot         DEVFS_MOUNT
```

even though it says it is not needed?  Also since i have my disks setup for raid i'm guessing i have to rewrite my raidtab?  Do i have to remake the raid arrays too, or can i just remount them?  If i remake the raid arrays will that erase all the data on them essentially forcing me to reinstall the whole system.  If so thank god(or the kind folks at gentoo) for stage3 builds?

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## taskara

yes, in the gentoo install docs is says you NEED devfs, and you need to auto mount it at boot.

you need to write your /etc/raidtab, but gentoo should re-build them for you on boot.

to re-initialise an array you make sure your raidtab is correct, then run 

```
raidstart /dev/mdx
```

----------

