# [solved]kernel panic problems on 2.6.36-gento-r5

## burwoad

It's a Thinkstation 6493. When booting, it shows :

```
VFS: Cannot open root device "sdf3" or unknown-block (2,0)

Please append a correct "root=" boot option; here are the available partitions:

0b00    1048575 sr0 driver: sr

Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(2,0)

Pid: 1, comm: swapper Not tainted 2.6.36-gentoo-r5 #4

Call Trace:

[<ffffffff814ada69>] panic+0x8c/0x194

......
```

the output of lspci is:

```
00:00.0 Host bridge: Intel Corporation 5400 Chipset Memory Controller Hub (rev 20)

00:01.0 PCI bridge: Intel Corporation 5400 Chipset PCI Express Port 1 (rev 20)

00:05.0 PCI bridge: Intel Corporation 5400 Chipset PCI Express Port 5 (rev 20)

00:09.0 PCI bridge: Intel Corporation 5400 Chipset PCI Express Port 9 (rev 20)

00:10.0 Host bridge: Intel Corporation 5400 Chipset FSB Registers (rev 20)

00:10.1 Host bridge: Intel Corporation 5400 Chipset FSB Registers (rev 20)

00:10.2 Host bridge: Intel Corporation 5400 Chipset FSB Registers (rev 20)

00:10.3 Host bridge: Intel Corporation 5400 Chipset FSB Registers (rev 20)

00:10.4 Host bridge: Intel Corporation 5400 Chipset FSB Registers (rev 20)

00:11.0 Host bridge: Intel Corporation 5400 Chipset CE/SF Registers (rev 20)

00:15.0 Host bridge: Intel Corporation 5400 Chipset FBD Registers (rev 20)

00:15.1 Host bridge: Intel Corporation 5400 Chipset FBD Registers (rev 20)

00:16.0 Host bridge: Intel Corporation 5400 Chipset FBD Registers (rev 20)

00:16.1 Host bridge: Intel Corporation 5400 Chipset FBD Registers (rev 20)

00:1b.0 Audio device: Intel Corporation 631xESB/632xESB High Definition Audio Controller (rev 09)

00:1c.0 PCI bridge: Intel Corporation 631xESB/632xESB/3100 Chipset PCI Express Root Port 1 (rev 09)

00:1d.0 USB Controller: Intel Corporation 631xESB/632xESB/3100 Chipset UHCI USB Controller #1 (rev 09)

00:1d.1 USB Controller: Intel Corporation 631xESB/632xESB/3100 Chipset UHCI USB Controller #2 (rev 09)

00:1d.2 USB Controller: Intel Corporation 631xESB/632xESB/3100 Chipset UHCI USB Controller #3 (rev 09)

00:1d.3 USB Controller: Intel Corporation 631xESB/632xESB/3100 Chipset UHCI USB Controller #4 (rev 09)

00:1d.7 USB Controller: Intel Corporation 631xESB/632xESB/3100 Chipset EHCI USB2 Controller (rev 09)

00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev d9)

00:1f.0 ISA bridge: Intel Corporation 631xESB/632xESB/3100 Chipset LPC Interface Controller (rev 09)

00:1f.1 IDE interface: Intel Corporation 631xESB/632xESB IDE Controller (rev 09)

00:1f.2 SATA controller: Intel Corporation 631xESB/632xESB SATA AHCI Controller (rev 09)

00:1f.3 SMBus: Intel Corporation 631xESB/632xESB/3100 Chipset SMBus Controller (rev 09)

05:00.0 VGA compatible controller: nVidia Corporation G80 [Quadro FX 4600] (rev a2)

09:00.0 PCI bridge: Intel Corporation 6311ESB/6321ESB PCI Express Upstream Port (rev 01)

09:00.3 PCI bridge: Intel Corporation 6311ESB/6321ESB PCI Express to PCI-X Bridge (rev 01)

0a:00.0 PCI bridge: Intel Corporation 6311ESB/6321ESB PCI Express Downstream Port E1 (rev 01)

0a:01.0 PCI bridge: Intel Corporation 6311ESB/6321ESB PCI Express Downstream Port E2 (rev 01)

0a:02.0 PCI bridge: Intel Corporation 6311ESB/6321ESB PCI Express Downstream Port E3 (rev 01)

0f:00.0 Ethernet controller: Intel Corporation 80003ES2LAN Gigabit Ethernet Controller (Copper) (rev 01)

0f:00.1 Ethernet controller: Intel Corporation 80003ES2LAN Gigabit Ethernet Controller (Copper) (rev 01)

1f:00.0 SCSI storage controller: LSI Logic / Symbios Logic SAS1068E PCI-Express Fusion-MPT SAS (rev 04)

20:05.0 FireWire (IEEE 1394): Texas Instruments TSB43AB22/A IEEE-1394a-2000 Controller (PHY/Link)
```

The menuconfig of the ATA drivers part is:

```
--- Serial ATA and Parallel ATA drivers

[*] Verbose ATA errors reporting

[*] ATA ACPI Support

[*] SATA Port Multiliers support

...

<*> AHCI SATA support

<*> ATA SFF support

...

[*] ATA BMDMA support

...

<*> Intel ESB, ICH, PIIX3, PIIX4, PATA/SATA support

...

<*> Intel PATA old PIIX support

...

<*> Intel PATA MPIIX support

...
```

well, the ... part means all the items in the interval is unchosen.

the grub.conf:

```
default 0

timeout 30

#splashimage=(hd0,0)/boot/grub/splash.xpm.gz

title Gentoo Linux 2.6.36-r5

root (hd1,0)

kernel /boot/kernel-2.6.36-gentoo-r5 root=/dev/sdf3
```

and the fstab:

```
/dev/sdf1    /boot    ext3    defaults,noatime    1 2

/dev/sdf2    none    swap    sw    0 0

/dev/sdf3    /    ext3    noatime    0 1

```

I am not sure which part is wrong, so just post all the configuration out. Can anybody help me? Many thanks in advance.Last edited by burwoad on Wed Jan 19, 2011 2:28 am; edited 1 time in total

----------

## krinn

it shows the kernel found your dvd/cdrom drive sr0 but no other partitions.

1/ your hdd is connect to your sas controller, and you forget to build the driver for the sas controller. You can ask lspci -k to get its name and then look in your .config for its presence.

2/ your hdd is connect to the pata controller and any of those (Intel ESB, ICH... or Intel Pata old pixx or intel PATA MPIIX) take controll of the pata ressource and prevent the ATA SFF driver doing its task.

You can check that in your dmesg, ATA SFF should appears first

3/ your hdd is dead/unconnect... you can control that in your bios

4/ bad partition/no partition, you can control that with fdisk

5/ udev can't create the links for your partitions because of bad kernel option (bad SYSFS_DEPRECATED*), you can also check that in dmesg: if you see your controller detecting the drive as per example (/dev/sda) and then no reference to /dev/sda1...). You will see the same if your drive have no/bad partitions.

Might be something else i'm not thinking of, but you get the most cases now.

by guessing chance order i would say check : 5-2-4-3-1

----------

## Jaglover

 *Quote:*   

> Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(2,0) 

 

IMO this error comes way before udev kicks in. It means kernel is unable to talk to the HDD controller. Device with major number 2 is floppy controller. 2,0 is first floppy drive, kernel has floppy support built in and is trying it as last resort. So I'd exclude 3, 4, 5.

----------

## burwoad

3. my hdd must be connected, since I have install a windows system in another partition, it works fine.

4. I am sure the partition is OK.

5. in the dmesg output, I found this:

```
kjournald starting.  Commit interval 5 seconds

EXT3-fs (sdf2): using internal journal

EXT3-fs (sdf2): mounted filesystem with writeback data mode

kjournald starting.  Commit interval 5 seconds

EXT3-fs (sdf1): using internal journal

EXT3-fs (sdf1): mounted filesystem with writeback data mode
```

here the sdf2 comes first, as i repartitioned the disk hours ago, all things were kept almost the same. so the partition had already been detected.

2. i have not found any strings like "ATA SFF" or "ata sff" in the dmesg output.

so it is due to the problem no. 2?

I tried to rebuild the kernel without any item related to "PATA", but the system is just unable to boot up, the same error pumped out when booting.

----------

## VoidMage

PATA parts are probably required - once again 'lspci -k'.

Perhaps pastebin your kernel config.

----------

## burwoad

 *VoidMage wrote:*   

> PATA parts are probably required - once again 'lspci -k'.
> 
> Perhaps pastebin your kernel config.

 

the lspci -k pumps:

http://pastebin.com/afa777Ci

the .config is:

http://pastebin.com/UMKBBLAm

----------

## burwoad

Is it the case 1?

the lspci have checked out:

```
00:1f.1 IDE interface: Intel Corporation 631xESB/632xESB IDE Controller (rev 09)

00:1f.2 SATA controller: Intel Corporation 631xESB/632xESB SATA AHCI Controller (rev 09) 

1f:00.0 SCSI storage controller: LSI Logic / Symbios Logic SAS1068E PCI-Express Fusion-MPT SAS (rev 04) 
```

These 3 controllers are all about the HDD, is that so? And which item(s) should I chose in the kernel for bootable one?

----------

## Suicidal

If you are using genkernel 3.4.11 there is a bug in it where it does not correctly honor --kernel-config. It appears to be loading generic configs from /usr/share/genkernel.

I noticed it last night when it kept setting the processor type to generic and my config is core2.

----------

## burwoad

It's solved.

I found it is a LSI Logic SAS hdd. So as others do, i enabled the kernel items like Fusion MPT device support for SAS such things. But after that, I found it is still unbootable. But when the screen pomps  error message like "Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(2,0)", I also see  strings like "... sdb1 ... 88326 ..." "... sdb2 ... 48243195..." in the top of the screen. Things seem so queer, when I install gentoo by a livecd(an Archlinux CD, and I have also tried Ubuntu also), the lable was sdf, how could it changed to sdb? And from the number in line, I confirmed that the sdb2 must be the partion created in the livecd, since they have the same volume, and so is sdb1 to sdf1.

As it was, I chroot into the system by livecd again, and alter all the "sdf"s in fstab and grub.conf to "sdb". After rebooting, the system start up finally.

OK, such a boot disater is solved finally, which confused me so many days. Thanks for all the help provided to me.

But I still have a question, that is: how could the volume labels differ in the booting period and in livecd?

----------

## Jaglover

burwoad,

those are not labels. They are device nodes. Normally, the first drive on first controller that gets initialized becomes sda, second drive becomes sdb and so on. As you can see, it depends on your kernel configuration.

----------

