[Clfs-support] Kernel unable to mount root fs

[Andreas Hofer]

Yeah, that is it. Thanks a lot for reminding me. That brought me a step
further. sda now is detected and init starts, though I have some other
problem now. Great, thanks again.

Andreas

-------- Original Message  --------
Subject: [Clfs-support] Kernel unable to mount root fs
From: Petric Frank <pfrank at gmx.de>
To: clfs-support at lists.cross-lfs.org
Date: Donnerstag, 06. Dezember 2007 09:37:21

> 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
>>
>> _______________________________________________
>> Clfs-support mailing list
>> Clfs-support at lists.cross-lfs.org
>> http://lists.cross-lfs.org/listinfo.cgi/clfs-support-cross-lfs.org
> 
> 
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