[Clfs-support] Kernel unable to mount root fs

[Petric Frank]

Hello,

only a guess - do you see your hard disk (i.e. flash) listed on the screen 
when booting ?

I often boot from an external USB hard disk and it takes often a few seconds 
between loading the USB support by the kernel and detecting the hard disk.
So i added a kernel parameter "rootdelay=<delay>" to grubs's menu.lst. With 
this option the kernel waits <delay> seconds to give the USB subsystem the 
chance to detect the USB hard disk.

Hope that helps.

regards
  Petric

On Donnerstag, 6. Dezember 2007, Andreas Hofer wrote:
> Good morning folks,
>
> I finally managed to install CLFS (embedded version, following the book)
> onto a USB (flash) disk and also configured GRUB. But, the boot process
> stops when the kernel tries to mount the root filesystem. The kernel
> messages are:
>
> ============================================================
> VFS: Cannot open root device "sda1" or unknown-block(0,0)
> Please append a correct "root=" boot option
> Kernel panic - not syncing: VFS: Unable to mount root fs on
> unknown-block(0,0)
> ============================================================
>
> The relevant entry in GRUB's menu.lst is:
> kernel /boot/clfskernel-2.6.20.1-DMP root=/dev/sda1
>
> The root partition is of type ext2, so I included e2fs_stage1_5 in
> /boot/grub.
>
> Since the disk is a USB flash device, the kernel has following feature
> compiled in:
>
> Device drivers / USB support :
> 	Support for Host-side USB
> 	USB device filesystem
> 	EHCI HCD (USB 2.0) support
> 	OHCI HCD support
> 	USB mass storage support
> Device drivers / SCSI device support :
> 	SCSI device support
> 	SCSI disk support
> File systems:
> 	Second extended fs support
> 	Ext3 journaling file system support
>
> I thought I had everything "on board" to mount the root fs.
>
> Any idea somebody?
>
> Andreas
>
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