Yes, thanks, that did it,
Helmut
On 06/25/2016 10:19:12 PM, Tom H wrote:
On Sat, Jun 25, 2016 at 2:33 PM, Helmut Jarausch <[email protected]>
wrote:
>
> I'm a dino since I still use grub-1 but I prefer recent kernels
(currently
> 4.70-rc4)
>
> I don't understand the 'root=' option on the boot line like
> kernel /boot/vmlinuz-4.7.0-rc4 root=/dev/sda1
>
> Here my bad experience:
>
> Having booted by SystemRescueCD from the cdrom device, my root
device is
> labelled /dev/sda1
> BUT trying to use that on the kernel boot line fails (the kernel
cannot
> find the root file system)
>
> By trial and error I've found that I have to use root=/dev/sdb1
>
> but if I plug in an external drive (via USB) this doesn't work any
more.
>
> So, I came up with root=UUID=uuid_number of the root file system.
>
> But to my surprise I now got a kernel panic
> syncing: VFS: unable to mount root fs on unknown block(0,0)
>
> So, please tell me what I'm missing?
Are you using an initramfs? You can't use "root=UUID=uuid" if you
don't.
You can use "root=PARTUUID=partuuid" where
on an msdos-labeled disk:
# findmnt / -o TARGET,SOURCE,PARTUUID
TARGET SOURCE PARTUUID
/ /dev/sda1 0006c8d7-01
on a gpt-labeled disk:
# findmnt / -o TARGET,SOURCE,PARTUUID
TARGET SOURCE PARTUUID
/ /dev/sda3 41e9268f-484a-43e2-ae81-54d8c84119e0
