problem with gentoo

linus johann · 09-13-2005, 12:03 PM

hi everyone!

i just finished "installing" gentoo using the genkernel option... now after i rebooted the system, i get a "The root block device is unspecified or not detected!" ... "Please specify a device to boot, or "shell" for a shell"..

what do i need to do? do i have to do the install all over again??

please help! it took me a long time... i hope i dont have to do it all over again

jtshaw · 09-13-2005, 12:09 PM

You don't have to do it all over again.

Boot off the install cd, remount your partitions (remount, NOT reformat

), and double check the "installing a bootloader" part of the installation. It sounds like you forgot the root=/dev/hdxy (where x and y correspond to your / partition) in the grub.conf on the kernel line.

linus johann · 09-13-2005, 12:17 PM

uh.. see, im new to this.. can you tell me how to do that?

what commands am i gonna issue to the console??

Thanks

jtshaw · 09-13-2005, 12:24 PM

All of this is taken from the Gentoo Install Handbook. If for some reason you didn't, the best thing to do is going step by step in the handbook and do exactly what it tells you.

Mounting you partitions:

Code:

mount /dev/hda3 /mnt/gentoo
mkdir /mnt/gentoo/boot
mount /dev/hda1 /mnt/gentoo/boot
mount -t proc none /mnt/gentoo/proc

The hda3 and hda1 device tags need to be change to whatever devices are you using. I assume you know this if you've gone through the installation before.

Then chroot:

Code:

chroot /mnt/gentoo /bin/bash
env-update
 * Caching service dependencies...
source /etc/profile

Then follow the bootloader section of the handbook..

linus johann · 09-13-2005, 12:37 PM

uh.. when i issue "chroot /mnt/gentoo /bin/bash", i receive an error

chroot: cannot run command "/bin/bash" : no such file or directory

thanks again

jtshaw · 09-13-2005, 12:43 PM

cd to /mnt/gentoo/ and type ls -la and tell us what is there. If you don't see a layout similar to this:

Code:

total 268
drwxr-xr-x   21 root root       520 Aug  9 16:18 .
drwxr-xr-x   21 root root       520 Aug  9 16:18 ..
drwxr-xr-x    2 root root      4016 Sep  6 10:10 bin
drwxr-xr-x    2 root root        96 May 17 16:46 boot
drwxr-xr-x   15 root root     13280 Sep 13 13:25 dev
drwxr-xr-x   71 root root      5112 Sep 13 11:22 etc
drwxr-xr-x    5 root root       144 Jul 29 09:01 home
drwxr-xr-x    9 root root      4216 Sep 12 08:38 lib
drwxr-xr-x    5 root root       144 May 10 11:11 mnt
drwxr-xr-x   10 root root       312 Aug 31 07:30 opt
dr-xr-xr-x  136 root root         0 Sep 12 15:53 proc
drwx------   20 root root      1120 Sep 13 13:16 root
drwxr-xr-x    2 root root      4664 Sep 13 11:21 sbin
drwxr-xr-x   10 root root         0 Sep 12 15:53 sys
drwxrwxrwt   30 root root    242600 Sep 13 13:39 tmp
drwxr-xr-x   14 root root       496 Aug 24 12:43 usr
drwxr-xr-x   13 root root       360 May  1 08:54 var

Then you either did something wrong mounting the parititons or you did something wrong in the original installation and not everything got installed correctly. Did you follow the handbook closely when you did the initial isntall?

linus johann · 09-13-2005, 12:46 PM

i got something similar to that.. though i can't still "chroot"..same error

jtshaw · 09-13-2005, 12:47 PM

Does /mnt/gentoo/bin/bash exist?

Did you have trouble chrooting when you did the installation the first time?

linus johann · 09-13-2005, 01:18 PM

i went over your instruction again and did it again.. now i got an error that says:

root=/dev/hd0,0
Error 11: Unrecogniced device string

Press any key to continue

maybe i should substitute "hd0,0" with "hd1,1"

my boot is hda1

what do you think is wrong with this??

jtshaw · 09-13-2005, 01:50 PM

What partition is your root partition? hda3?

You want it to say root=/dev/hda3 if hda3 is your / partition.

linus johann · 09-13-2005, 02:12 PM

right.. hda3 is my root.. okay i'll try that one.. will keep you posted

thanks again

linus johann · 09-13-2005, 02:18 PM

got this again:
The root block device is unspecified or not detected!" ... "Please specify a device to boot, or "shell" for a shell"

oh man!

jtshaw · 09-13-2005, 02:18 PM

Not a problem.

Just to make it clear about drive labels....

The kernel and linux in general uses tags like this, hda1, hda2, ect. The root=/dev/hda3 line is being passed into the kernel. When you see things like root (hd0,0) in grub.conf that is refereing to the grub device id's. Grub handles them differently. For instance, the first hard drive on the system's first partition is (hd0,0). The first harddrives 2nd partition is (hd0,1). The 2nd harddrives 3rd partition would be (hd1,2) and so on. Grub itself is the only thing that understands this. The tags in grub aren't tied to a particular bus. If I have a IDE HD and a SCSI HD and the IDE HD is usually hd0 removing it would then cause the SCSI HD to become hd0.

Can you show us your /boot/grub/grub.conf (or /boot/grub/menu.lst) file?

linus johann · 09-13-2005, 02:31 PM

default 0
timeout 30
splashimage=(hd0,0)/grub/splash.xpm.gz

title=Gentoo Linux 2.6.11-r3
root (hd0,0)
kernel /kernel-genkernel-x86-2.6.12-gentoo-r6 root=/dev/hda3 init=/linuxrc ramdisk=8192 real_root=/dev/hda3 udev
initrd /initramfs-genkernel-x86-2.6.12-gentoo-r6

linus johann · 09-13-2005, 06:55 PM