udev [ -f /dev/.udev.tdb ] test

Kevin P. Fleming kpfleming at linuxfromscratch.org
Fri Sep 24 18:47:54 PDT 2004

M.Canales.es wrote:

> In my system, QDI-P4I848P motherboard (chipset ICH5) with "Enchanced Mode" 
> activated in BIOS, and the libata driver compiled into the kernel (the SATA 
> ata_piix driver, not the PATA piix driver) I got a "kernel paninc: unable to 
> mount root filesystem" if I try to load the kernel directly, but boot fine 
> using a barebone initrd (created using the "initrd for LFS" hint from Jim 
> Gifford).

As mentioned in another response, this is likely the /dev/hda vs. 
/dev/sda issue. I have booted a number of systems using SATA drives on 
different types of controllers, including ICH5, and have never needed an 
initrd to be able to bring the system up.

There are really only two reasons an initrd would be needed that I'm 
aware of:

1) The required drivers are not compiled into the kernel, but are 
compiled as modules and are loaded at boot-time by some sort of script

2) The hardware being used is not probed/found/etc. quickly enough for 
the kernel to be able to use it (this is usually the issue with USB 
disks), and the initrd waits for the device to become available before 
allowing the boot process to continue

More information about the lfs-dev mailing list