installed slackware 12.2 onto a 4gig usb flashdrive. boots then stops

open-pc · 01-03-2009, 08:13 PM

i took my hard drives out, and stuck a 4gig usb flash. Booted the cd. and fdisk the drive. cfdisk it to linux partition. then ran setup. everything went find. during liloconfig, added the mbr to /dev/sda then added sda1 for root.

it booted to the splash screen and then loaded "linux" but it stop at at kernel panic: Cannot open root device "sda1" or unknown-block(0,0). i guess its a renaming thing but i can't figure out how to edit lilo to get it to open the root device. anyone try this or have a suggestion "thanks"

rvo · 01-03-2009, 10:24 PM

You may have to pass 'rootwait' as a kernel parameter, I had a similar problem when I installed a distro to my usb stick. If I'm correct, the kernel tries to boot from /dev/sdx, which is on an usb disk, but the kernel hasn't probed the usb subsystem yet, so with that option the kernel will wait for the root partition and then mount it.

From the kernel documentation:

Quote:

rootwait [KNL] Wait (indefinitely) for root device to show up.

Yalla-One · 01-03-2009, 11:55 PM

In addition to the advise above, you might also want to check that your kernel either has the USB subsystem compiled in, or that you have the correct kernel modules on an initrd for the sda1 to be found...

HerbertJ · 01-04-2009, 01:34 AM

This is how I get slack to boot off the USB, though if the kernel wait option will probably work, and makes more sense...

Create a initrd.gz file with mkinitrd. Remember to add the fstab file in

/boot/initrd-tree/etc/fstab

and point /dev/sda1 ( your partition ) to mount on /mnt.

You may also need to create block devices in

/boot/initrd-tree/dev

as I had to, but in some cases it is created automatically.

mknod /boot/initrd-tree/dev/sda b 8 0
mknod /boot/initrd-tree/dev/sda1 b 8 1

Change the "wait-for-root" file to something longer than 1.

echo 10 > /boot/initrd-tree/wait-for-root

Once the initrd.gz file has been created, add a line to your lilo.conf file for the initrd.

...
image = /boot/bzImage-2.6.28
root = /dev/sda1
label = 2.6.28
initrd = /boot/initrd.gz #Add this line
read-only
...

and run lilo and reboot.

Remember to add the "compact" option in lilo.conf to speed up booting off the USB device.

HerbertJ · 01-04-2009, 04:53 AM

I've tried appending "rootwait". I was unable to get it to work. I found another person that stated that they used "rootwait" and "scsi_mod.scan=1" in order to get another distribution to load off a USB drive. I also tried that, as "rootwait" by itself would sit there, waiting for a device that was never going to be detected. Unfortunately neither has worked for me and I'm still using initrd to mount the root device.