# [Solved] VFS: Unable to mount root fs on unknown-block 2-0

## da_weed

Hello. I'm trying to make fresh install of Gentoo with kernel 3.1.4 but i stuck with (i guess) sata configuration. Whatever I do I always end up with same error:

http://picpaste.com/pics/20111206_002-8p0gY9yF.1323205785.jpg

I have 2 hdd. First one (sda) is used for windows and second is Gentoo:

sdb1 for /boot with ext2

sdb2 for swap

sdb3 for / with ext3 and

sdb4 for /home with ext4

And yes i compiled kernel with ext2,ext3 and ext4 filesystems.

My motherboard is GA-MA785GM-US2H. 

lspci -v on livecd shows:

```
ATI Technologies Inc SB7x0/SB8x0/SB9x0 SATA Controller [AHCI mode]
```

 and kernel module "ahci". In chrooted environment points to the same module.

Device Drivers->Serial ATA and Parallel ATA drivers (sorry but copied straight from .config)

```

# Controllers with non-SFF native interface

#

CONFIG_SATA_AHCI=y

# CONFIG_SATA_AHCI_PLATFORM is not set

# CONFIG_SATA_INIC162X is not set

# CONFIG_SATA_ACARD_AHCI is not set

# CONFIG_SATA_SIL24 is not set

CONFIG_ATA_SFF=y

#

# SFF controllers with custom DMA interface

#

# CONFIG_PDC_ADMA is not set

# CONFIG_SATA_QSTOR is not set

CONFIG_ATA_BMDMA=y

#

# SATA SFF controllers with BMDMA

#

# CONFIG_ATA_PIIX is not set

# CONFIG_SATA_MV is not set

# CONFIG_SATA_NV is not set

# CONFIG_SATA_PROMISE is not set

# CONFIG_SATA_SIL is not set

# CONFIG_SATA_SIS is not set

# CONFIG_SATA_SVW is not set

# CONFIG_SATA_ULI is not set

# CONFIG_SATA_VIA is not set

# CONFIG_SATA_VITESSE is not set

#

# PATA SFF controllers with BMDMA

#

# CONFIG_PATA_ALI is not set

# CONFIG_PATA_AMD is not set

# CONFIG_PATA_ARASAN_CF is not set

# CONFIG_PATA_ARTOP is not set

CONFIG_PATA_ATIIXP=y

# CONFIG_PATA_ATP867X is not set

# CONFIG_PATA_CMD64X is not set

# CONFIG_PATA_CS5520 is not set

# CONFIG_PATA_CS5530 is not set

# CONFIG_PATA_CS5536 is not set

# CONFIG_PATA_EFAR is not set

# CONFIG_PATA_HPT366 is not set

# CONFIG_PATA_HPT37X is not set

# CONFIG_PATA_HPT3X2N is not set

# CONFIG_PATA_HPT3X3 is not set

# CONFIG_PATA_IT821X is not set

# CONFIG_PATA_JMICRON is not set

# CONFIG_PATA_MARVELL is not set

# CONFIG_PATA_NETCELL is not set

# CONFIG_PATA_NINJA32 is not set

# CONFIG_PATA_NS87415 is not set

# CONFIG_PATA_OLDPIIX is not set

# CONFIG_PATA_PDC2027X is not set

# CONFIG_PATA_PDC_OLD is not set

# CONFIG_PATA_RDC is not set

# CONFIG_PATA_SC1200 is not set

# CONFIG_PATA_SCH is not set

# CONFIG_PATA_SERVERWORKS is not set

# CONFIG_PATA_SIL680 is not set

# CONFIG_PATA_SIS is not set

# CONFIG_PATA_TRIFLEX is not set

# CONFIG_PATA_VIA is not set

# CONFIG_PATA_WINBOND is not set

#

# PIO-only SFF controllers

#

# CONFIG_PATA_MPIIX is not set

# CONFIG_PATA_NS87410 is not set

# CONFIG_PATA_RZ1000 is not set

#

# Generic fallback / legacy drivers

#

# CONFIG_PATA_ACPI is not set

# CONFIG_ATA_GENERIC is not set

# CONFIG_MD is not set

# CONFIG_TARGET_CORE is not set

# CONFIG_FUSION is not set

```

File Systems

```

#

# File systems

#

CONFIG_EXT2_FS=y

# CONFIG_EXT2_FS_XATTR is not set

# CONFIG_EXT2_FS_XIP is not set

CONFIG_EXT3_FS=y

# CONFIG_EXT3_DEFAULTS_TO_ORDERED is not set

# CONFIG_EXT3_FS_XATTR is not set

CONFIG_EXT4_FS=y

# CONFIG_EXT4_FS_XATTR is not set

# CONFIG_EXT4_DEBUG is not set

CONFIG_JBD=y

# CONFIG_JBD_DEBUG is not set

CONFIG_JBD2=y

# CONFIG_JBD2_DEBUG is not set

# CONFIG_REISERFS_FS is not set

# CONFIG_JFS_FS is not set

# CONFIG_XFS_FS is not set

# CONFIG_GFS2_FS is not set

CONFIG_FS_POSIX_ACL=y

CONFIG_FILE_LOCKING=y

CONFIG_FSNOTIFY=y

CONFIG_DNOTIFY=y

CONFIG_INOTIFY_USER=y

# CONFIG_FANOTIFY is not set

CONFIG_QUOTA=y

CONFIG_QUOTA_NETLINK_INTERFACE=y

# CONFIG_PRINT_QUOTA_WARNING is not set

# CONFIG_QUOTA_DEBUG is not set

CONFIG_QUOTA_TREE=y

# CONFIG_QFMT_V1 is not set

CONFIG_QFMT_V2=y

CONFIG_QUOTACTL=y

CONFIG_QUOTACTL_COMPAT=y

CONFIG_AUTOFS4_FS=y

# CONFIG_FUSE_FS is not set

CONFIG_GENERIC_ACL=y

```

my /etc/fstab

```
                                             

# /etc/fstab: static file system information.

#

# noatime turns off atimes for increased performance (atimes normally aren't 

# needed; notail increases performance of ReiserFS (at the expense of storage 

# efficiency).  It's safe to drop the noatime options if you want and to 

# switch between notail / tail freely.

#

# The root filesystem should have a pass number of either 0 or 1.

# All other filesystems should have a pass number of 0 or greater than 1.

#

# See the manpage fstab(5) for more information.

#

# <fs>         <mountpoint>   <type>      <opts>      <dump/pass>

# NOTE: If your BOOT partition is ReiserFS, add the notail option to opts.

/dev/sdb1      /boot      ext2      noauto,noatime   1 2

/dev/sdb3      /      ext3      noatime      0 1

/dev/sdb2      none      swap      sw      0 0

/dev/sdb4      /home      ext4      noatime      0 2

/dev/cdrom      /mnt/cdrom   auto      noauto,ro   0 0

#/dev/fd0      /mnt/floppy   auto      noauto      0 0

# glibc 2.2 and above expects tmpfs to be mounted at /dev/shm for 

# POSIX shared memory (shm_open, shm_unlink).

# (tmpfs is a dynamically expandable/shrinkable ramdisk, and will

#  use almost no memory if not populated with files)

shm         /dev/shm   tmpfs      nodev,nosuid,noexec   0 0

proc         /proc      proc      defaults   0 0

```

and my grub.conf:

```

                                             

# This is a sample grub.conf for use with Genkernel, per the Gentoo handbook

# http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=1&chap=10#doc_chap2

# If you are not using Genkernel and you need help creating this file, you

# should consult the handbook. Alternatively, consult the grub.conf.sample that

# is included with the Grub documentation.

default 0

timeout 10

splashimage=(hd1,0)/boot/grub/splash.xpm.gz

title Gentoo Linux 3.1.4-r1

root (hd1,0)

kernel /boot/kernel-3.1.4-r1 dev=/dev/sdb3

title Gentoo linux 3.1.4 (rescue) 

root (hd1,0)

kernel /boot/kernel-3.1.4-r1 dev=/dev/sdb3 init=/bin/bb

title Windows 7

rootnoverify (hd0,0)

makeactive

chainadrer +1

# vim:ft=conf:

```

Can someone help me configure this kernel because im struggling for 3 days with no luck. I even marked all modules for sata to be compiled into kernel with same error. TA.Last edited by da_weed on Thu Dec 08, 2011 5:39 pm; edited 1 time in total

----------

## gerard27

You have this in your grub.conf:

dev=/dev/sdb3

It should be root=/dev/sdb3.

Where did you get "dev=" ?

Hope this solves it?

Gerard.

----------

## da_weed

 *Quote:*   

> 
> 
> You have this in your grub.conf:
> 
> dev=/dev/sdb3
> ...

 

THX. Spot on mate. I knew it would be something stupid.

----------

## gerard27

You're welcome.

Please put solved in the title of thid thread.

Gerard.

----------

