Block device is not a valid root device

Nirva · n00b Joined: 13 Jan 2008 Posts: 7

Hay,

I'm trying to switch from Ubuntu to Gentoo, but I have a little problem while installing it.
I followed the handbook rather strictly.
Except, because I already had an existing Ubuntu installation, I assumed that I could just add another entry to mij /boot/grub/menu.lst.
This is how it looks :

...
title Gentoo Linux 2.6.23-r3
root (hd0,2)
kernel /boot/kernel-genkernel-x86-2.6.23-gentoo-r3 root=/dev/ram0 init=/linuxrc ramdisk=8192 real_root=/dev/sda3 udev
initrd /boot/initramfs-genkernel-x86-2.6.23-gentoo-r3
...

But when I try booting this, everything goes fine until he says :
Block Device /dev/sda3 is not a valid root device.
The root block device is unspecified or not detected.

I would be really happy if someone could help me...
Thanks....

Voltago · Posted: Sun Jan 13, 2008 3:38 pm Post subject:

So boot- and root-partition are one and the same in your setup? Can I see your partition layout?

Nirva · n00b Joined: 13 Jan 2008 Posts: 7

#:~$ df

/dev/sda1 59741148 44999468 12920876 78% /
varrun 517912 104 517808 1% /var/run
varlock 517912 0 517912 0% /var/lock
udev 517912 76 517836 1% /dev
devshm 517912 0 517912 0% /dev/shm
lrm 517912 34288 483624 7% /lib/modules/2.6.22-14-386/volatile
/dev/sda3 15357604 1387776 13969828 10% /mnt/gentoo

My bootloader is installed at /dev/sda and the gentoo kernel I'm trying to boot is at /dev/sda3.
I also have some swapspace at /dev/sda2, but this isn't listed. I don't know why...

Voltago · Posted: Sun Jan 13, 2008 4:18 pm Post subject:

A better choice to display a partition layout is

NeddySeagoon · Posted: Sun Jan 13, 2008 4:24 pm Post subject:

Nirva,

At the grub splash screen, press e to edit in in memory grub.conf and change
kernel /boot/kernel-genkernel-x86-2.6.23-gentoo-r3 root=/dev/ram0 init=/linuxrc ramdisk=8192 real_root=/dev/sda3 udev
to
kernel /boot/kernel-genkernel-x86-2.6.23-gentoo-r3 root=/dev/ram0 init=/linuxrc ramdisk=8192 real_root=/dev/hda3 udev
thats sda3 to hda3.

With some chipsets, when you build a PATA and a SATA driver, neither works properly but the device appears and runs slowly as an IDE device, even if its really SATA.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Nirva · n00b Joined: 13 Jan 2008 Posts: 7

Thanks for all the help I'm getting.

To make things clear :

Device Boot Start End Blocks Id System
/dev/sda1 1 7556 60693538+ 83 Linux
/dev/sda2 9469 9729 2096482+ 82 Linux swap / Solaris
/dev/sda3 7557 9468 15358140 83 Linux

I just tried this :

title Gentoo Linux noframebuffer
root (hd0,2)
kernel /boot/kernel-genkernel-x86-2.6.23-gentoo-r3 root=/dev/sda3

And this gave me a new error :

VFS : Cannot open root device "sda3" or unknown block(0,0)
Please append a correct "root=" boot option.

I also tried this

title Gentoo Linux noframebuffer
root (hd0,2)
kernel /boot/kernel-genkernel-x86-2.6.23-gentoo-r3 root=/dev/sda3:
initrd /boot/initramfs-genkernel-x86-2.6.23-gentoo-r3

And it gave me the previous error.

I'll now try the solution from NeddySeagoon and post my results within 5 minutes.

Nirva · n00b Joined: 13 Jan 2008 Posts: 7

Oke, I tried the solution from NeddySeagoon :

title Gentoo Linux 2.6.23-r3
root (hd0,2)
kernel /boot/kernel-genkernel-x86-2.6.23-gentoo-r3 root=/dev/ram0 init=/linuxrc ramdisk=8192 real_root=/dev/hda3 udev
initrd /boot/initramfs-genkernel-x86-2.6.23-gentoo-r3

It worked, because it passed the point where it used to get stuck. But now I get an other error.

A little further he says :
Failed to open device /dev/sda3 : no such file or directory.

Voltago · Posted: Sun Jan 13, 2008 4:41 pm Post subject:

That is your /etc/fstab. Change there sda3 into hda3, too.

NeddySeagoon · Posted: Sun Jan 13, 2008 4:50 pm Post subject:

Nirva,

Fix your kernel. When you operate a SATA device with a driver than makes it look like IDE, there is no DMA support so it between 10x and 20x slower than when its operated with the correct driver. That will ruin your Gentoo experiance

As Voltago says, your /etc/fstab entry is still for sda3.
This means the boot up fsck will fail, which is your new problem.

Post your lspci output so we can advise proper kernel settings.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Nirva · n00b Joined: 13 Jan 2008 Posts: 7

Thank you very very much.
I finally booted into my gentoo !
I'm very pleased that I can go on now !

NeddySeagoon · Posted: Sun Jan 13, 2008 5:16 pm Post subject:

Nirva,

Put fixing your kernel near the top of your list of things to do.
Yes, you can go on now but it will be very slow for you.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Nirva · n00b Joined: 13 Jan 2008 Posts: 7

I indeed noted that DMA was not activated.
Here is my lspci.

00:00.0 Host bridge: Intel Corporation Mobile 915GM/PM/GMS/910GML Express Processor to DRAM Controller (rev 03)
00:01.0 PCI bridge: Intel Corporation Mobile 915GM/PM Express PCI Express Root Port (rev 03)
00:1d.0 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #1 (rev 03)
00:1d.1 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #2 (rev 03)
00:1d.2 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #3 (rev 03)
00:1d.3 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #4 (rev 03)
00:1d.7 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB2 EHCI Controller (rev 03)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev d3)
00:1e.2 Multimedia audio controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) AC'97 Audio Controller (rev 03)
00:1f.0 ISA bridge: Intel Corporation 82801FBM (ICH6M) LPC Interface Bridge (rev 03)
00:1f.2 IDE interface: Intel Corporation 82801FBM (ICH6M) SATA Controller (rev 03)
00:1f.3 SMBus: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) SMBus Controller (rev 03)
01:00.0 VGA compatible controller: ATI Technologies Inc M22 [Mobility Radeon X300]
03:00.0 Ethernet controller: Broadcom Corporation BCM4401-B0 100Base-TX (rev 02)
03:01.0 CardBus bridge: Ricoh Co Ltd RL5c476 II (rev b3)
03:01.1 FireWire (IEEE 1394): Ricoh Co Ltd R5C552 IEEE 1394 Controller (rev 0

03:01.2 Generic system peripheral [0805]: Ricoh Co Ltd R5C822 SD/SDIO/MMC/MS/MSPro Host Adapter (rev 17)
03:03.0 Network controller: Intel Corporation PRO/Wireless 2200BG Network Connection (rev 05)

lskywalker · n00b Joined: 14 Jan 2008 Posts: 2

Hello,

I actually have the same problem (also changing from Ubuntu) and would be glad to see a solution here

I tried to compile "serial ATA (prod) and parallel ATA (experimental) drivers" with genkernel (not as module, but into the kernel), but it didn't work.

Which entry do I have to select?

[EDIT]lspci shows:

luqas · Posted: Mon Jan 14, 2008 4:28 pm Post subject:

lskywalker: Did you select NVIDIA SATA support under Serial ATA (prod) and Parallel ATA (experimental) drivers? Make sure you did like above and compile it into the kernel and not as a module.

lskywalker · n00b Joined: 14 Jan 2008 Posts: 2

Thanks, it worked perfectly!

NeddySeagoon · Posted: Mon Jan 14, 2008 8:59 pm Post subject:

Nirva,

You need these kernel settings for your SATA drive.
The post says Intel ICH7 but it applies to ICH6 and later.

You will have to swap your grub.conf and fstab back the sda too
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

David Duvall

Struggled with this problem of not finding my SATA drives for a while. By turning off ACPI in the bios the system booted without any problem.

Lance · Tux's lil' helper Joined: 02 Apr 2004 Posts: 125

I had the same problem and fixed it following NeddySeagoon's instruction.

Thank you NeddySeagoon!
_________________
choose Gentoo, choose freedom