# [Solved] VFS kernel panic

## calif

Hi

I've just installed Gentoo and I have following problem when booting:

 *Quote:*   

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

 

kernel: 4.1.15-gentoo-r1

I guess it's a problem with my kernel - because this error looks like the kernel can't see my disks?

But... I'm compiling my kernel with new modules for, like, 40 time, really... It doesn't work.

lspci:

```

00:00.0 Host bridge: Intel Corporation 4th Gen Core Processor DRAM Controller (rev 06)

00:01.0 PCI bridge: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor PCI Express x16 Controller (rev 06)

00:02.0 VGA compatible controller: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics Controller (rev 06)

00:03.0 Audio device: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor HD Audio Controller (rev 06)

00:14.0 USB controller: Intel Corporation Device 8cb1

00:16.0 Communication controller: Intel Corporation Device 8cba

00:1a.0 USB controller: Intel Corporation Device 8cad

00:1b.0 Audio device: Intel Corporation Device 8ca0

00:1c.0 PCI bridge: Intel Corporation Device 8c90 (rev d0)

00:1c.2 PCI bridge: Intel Corporation Device 8c94 (rev d0)

00:1c.3 PCI bridge: Intel Corporation Device 8c96 (rev d0)

00:1d.0 USB controller: Intel Corporation Device 8ca6

00:1f.0 ISA bridge: Intel Corporation Device 8cc4

00:1f.2 SATA controller: Intel Corporation Device 8c82

00:1f.3 SMBus: Intel Corporation Device 8ca2

01:00.0 VGA compatible controller: NVIDIA Corporation Device 13c2 (rev a1)

01:00.1 Audio device: NVIDIA Corporation Device 0fbb (rev a1)

03:00.0 Ethernet controller: Qualcomm Atheros Killer E2200 Gigabit Ethernet Controller (rev 10)

04:00.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 41)

```

lspci -v:

```
https://bpaste.net/show/eced84f9f036
```

my .config:

```
https://bpaste.net/show/d93c66bd55d9
```

grub.cfg:

```
https://bpaste.net/show/c05bc5754023
```

fstab:

```
https://bpaste.net/show/d0c3f9234687
```

(0,0) is my HDD, it is clean, just formatted - sda

(1,0) is my SSD with linux - sdb

(2,0) is my SSD with windows10 - sdc

I guess... Is it obvious that the numerical order is as alphabetic order (0,1,2 == a,b,c)?

Could you please help me? I can't stand it anymore  :Smile: 

PS.

Motherboard if needed: Gigabyte z97x-gaming-3Last edited by calif on Tue Feb 16, 2016 11:18 pm; edited 1 time in total

----------

## NeddySeagoon

calif,

Lets look at your kernel.

```
CONFIG_MSDOS_PARTITION=y

CONFIG_EFI_PARTITION=y
```

Thats good. The kernel can read your partition tables.

```
CONFIG_IDE=y
```

Thats the Depreciated IDE drivers menu and is a verybadthing.

If it was the only driver you had, you would not get any IDE /dev/hda and friends nodes.

```
CONFIG_SCSI=y

CONFIG_BLK_DEV_SD=y

CONFIG_BLK_DEV_SR=y

CONFIG_BLK_DEV_SR_VENDOR=y

CONFIG_CHR_DEV_SG=y
```

Good but only the first two are essential to boot.

```
CONFIG_ATA=y

CONFIG_SATA_AHCI=y
```

Thats the driver for your SATA chipset.

You may need 

```
# CONFIG_SATA_AHCI_PLATFORM is not set
```

on.  I have two different motherboards with the same chipset. One needs it the other does not.  

Turn off 

```
CONFIG_EXT4_DEBUG=y
```

All debug options increase logspam. Some interfere with normal operation too.

Unless you are debugging the kernel feature in question, debug options need to be off.

Only you know if you need

```
CONFIG_EXT4_ENCRYPTION=y

CONFIG_EXT4_FS_ENCRYPTION=y
```

They are not required for a handbook install.

Turn off 

```
CONFIG_NTFS_RW=y
```

It only allows modifying a NTFS file in place providing the filesize does not change.

```
emerge ntfs-3g
```

if you want to write NTFS volumes.

 *Quote:*   

> I guess... Is it obvious that the numerical order is as alphabetic order (0,1,2 == a,b,c)? 

 

That's not true as the kernel HDD discovery order and BIOS HDD discovery order need not be the same.

Often, the BIOS reports the boot drive as drive 0, regardless of which drive it actually is. 

As you get a kernel to boot, grub must be doing its stuff.

----------

## j000

Because I did this mistake before, I need to ask. Do you mount /boot before compiling kernel? Because with noauto in fstab...

Also, have you tried to temporarily alter command line in grub to root=/dev/sda3 or sdc and see if this maybe helps?

----------

## NeddySeagoon

calif,

j000s post reminds me ...

Does the panic continue with 

Unable to find root device in <list_of_block_devices>.

The <list_of_block_devices> may be empty too

----------

## calif

 *NeddySeagoon wrote:*   

> calif,
> 
> Lets look at your kernel.
> 
> ```
> ...

 

It helped! Thank you very much! I wish I could solve those problem like this.  :Wink: ))

Now I'm going to repair my GRUB - I found different version of how to install it on gentoo, don't know which one to use, and also that makes my UEFI showing 2 diffrent GRUBs installations and one of those doesn't work.

Hmm, but currently my grub2-mkconfig can't find my windows even when os-prober is installed  :Sad: 

More here: https://forums.gentoo.org/viewtopic-p-7881340.html#7881340

----------

