Re: Bug#397950: initramfs-tools: incorrectly tries to use external disk as root FS instead of internal disk

[maximilian attems <maks@sternwelten.at>]

reassign 397950 debian-installer-utils
stop

On Fri, Nov 10, 2006 at 05:45:49PM +0100, Laurent Bonnaud wrote:
> Hi,
> 
> this system usually boots from an internal SATA disk (/dev/sda).  I
> recently added an external IEEE1394 disk and when I tried to reboot
> the system, it failed.  /dev/sda had become the external disk and the
> internal disk had become /dev/sdb therefore the initramfs did not find
> the correct root FS.
> 
> I could change grub and the fstab to use /dev/sdb instead of /dev/sda,
> but I do not want to because I would like to be able to boot my system
> even if the external disk is unplugged.
> 
> I could boot my system with the external disk unplugged and plug it
> later, but this would not allow me to perform remote reboots.
> 
> Ubuntu solves this problem by using root=UUID=<something> instead of
> root=/dev/<something> on the kernel command line.
> 
> A simpler fix would be to change the loading order of kernel modules.
> According to the list below, the 1394 modules are loaded before the
> sata modules.  This order could probably be reversed without harming
> anybody.

the kernel never guarantees device ordering, this is an userspace
policy to implement.
initramfs-tools support to boot via uuid. the installer folks know
the ubuntu patches for it, so reassigning.
 
> I have another system (amd64 architecture) with an external IEEE1394
> disk and I have no problem because curiously the modules are loaded in
> a different order:
 
<snipp>
> Do you know why ?  This other system boots on /dev/md0, which avoids
> the problem altogether.

mdadm uses uuid too,
but needs some udev fixes to be completly migrated allowing uuid root.
 
> I did not flag this bug as "grave" because there is a simple
> work-around (unplug the external disk), but an unbootable system at
> least deserves to be "important".

it is currently the most report bug.. so surely a duplicate,
anyway etch should not ship without uuid usage.

regards

-- 
maks