Welcome to Linux Forums! With a comprehensive Linux Forum, information on various types of Linux software and many Linux Reviews articles, we have all the knowledge you need a click away, or accessible via our knowledgeable members.
Write an article for LinuxForums Today! Win Great Prizes!
ERROR: VFS: Cannot open root device or unknown-block(0,0)
Hi,
So last night after getting errors trying to install wireless-tools for my laptop during the Gentoo installation, I removed the -Wall -Werror flags I had in my CXXFLAGS and compiled everything like a charm. When I try to boot Gentoo, however, I get the following error:
Code:
VFS: Cannot open root device "sdb4" or unknown-block(0,0)
Please append a correct "root=" boot option
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
Now I've checked and double-checked my fdisk partition table and my grub boot menu, and cross-referenced it with the example partition scheme in the Handbook.
My fdisk table is the following:
Code:
/dev/sdb1 is swap space
/dev/sdb2 is ReiserFS running Ubuntu
/dev/sdb3 is /boot for Gentoo
/dev/sdb4 is / for Gentoo
My GRUB entry for Gentoo is:
Code:
title=Gentoo Linux 2.6.20-r8
root (hd1,2) [hd1,2 is sdb3 which is my Gentoo boot]
kernel /boot/kernel-2.6.20-gentoo-r8 root=/dev/sdb4 [sdb4 is my / partition]
The manual has the following partition scheme:
Code:
/dev/hda1 is boot
/dev/hda2 is swap
/dev/hda3 is /
The manual offers the following as an example for GRUB:
Code:
title=Gentoo Linux 2.6.19-r5
root (hd0,0)
kernel /boot/kernel-2.6.19-gentoo-r5 root=/dev/hda3
Therefore, root (hd0,0) for them is like root (hd1,2) for me
Therefore root=/dev/hda3 for them is like root=/dev/sdb4 for me
Just like I have already. And it still won't load. I'm out of ideas, and I'm hoping someone out there can help me out. I've had great help from a few people already on other topics, and this one was started in the wireless-tools thread of mine, but I figured I'd put it here since it's a different issue.
how many Harddisks are plugged-in your machine?
why SATA disk is sdb? if you have only one SATA disk, it should be sda.
post the contents of Gentoo's /boot/grub/device.map file and output of fdisk -l command.
__________________
It takes a lot of time to be a genius, you have to sit around so much doing nothing, really doing nothing. - Gertrude Stein New Users:Read This First
The sdb is because I have two hard disks. Toshiba Qosmio G30 for ya. windows on one disk, linux on the other. I'll post what you want in about an hour. Cheers.
there must be a device.map file in /boot/grub folder. GRUB looks in device.map file for disk names.
according to output of 'fdisk -l' command and contents of /etc/fstab, contents of device.map file should be
Code:
(hd0) /dev/sda
(hd1) /dev/sdb
if there isn't any device.map file in Gentoo's /boot/grub, create new and type above code.
__________________
It takes a lot of time to be a genius, you have to sit around so much doing nothing, really doing nothing. - Gertrude Stein New Users:Read This First
I checked Ubuntu's grub and the file was there, so I checked the contents via cat and copied the file to /gentoo/boot/grub. I reboot my computer and trying getting into Gentoo again, but nothing. I'm assuming what you told me to do wasn't the end of my woes. So what next?
The following is Ubuntu's menu.lst, however it is not the current one grub is using.
Code:
title Ubuntu, kernel 2.6.15-28-386
root (hd1,1)
kernel /boot/vmlinuz-2.6.15-28-386 root=/dev/sdb2 ro quiet splash
initrd /boot/initrd.img-2.6.15-28-386
savedefault
boot
### END DEBIAN AUTOMAGIC KERNELS LIST
# This is a divider, added to separate the menu items below from the Debian
# ones.
title Other operating systems:
root
# This entry automatically added by the Debian installer for a non-linux OS
# on /dev/sda1
title Windows XP Media Center Edition
root (hd0,0)
savedefault
makeactive
chainloader +1
The current one grub is using in in gentoo's /boot/grub, which is this:
Code:
title= Gentoo Linux
root (hd1,2)
kernel /boot/kernel-2.6.20-gentoo-r8 root=/dev/sdb4
title= Ubuntu Linux
root (hd1,1)
kernel /boot/vmlinuz-2.6.15-28-386 root=/dev/sdb2 ro quiet splash
initrd /boot/initrd.img-2.6.15-28-386
boot
title= Windows XP Media Center Edition
root (hd0,0)
makeactive
chainloader +1
A few quick questions to try and narrow down the problem...
-Do Windows and Ubuntu boot using this grub.conf?
-Has Gentoo ever booted before from this grub.conf?
I ask these because this looks to me like more of a kernel problem than a grub problem. The grub.conf looks correct to me assuming you placed the bzImage in the correct place. Sorry if I'm restating anything anyone else said or something you've answered before, but skimming through the posts, I didn't see anything mentioned about your kernel.
I ask these because this looks to me like more of a kernel problem than a grub problem. The grub.conf looks correct to me assuming you placed the bzImage in the correct place. Sorry if I'm restating anything anyone else said or something you've answered before, but skimming through the posts, I didn't see anything mentioned about your kernel
I Agree. something is wrong with kernel only. grub.conf file is configured correctly. problem is coz of kernel only.
__________________
It takes a lot of time to be a genius, you have to sit around so much doing nothing, really doing nothing. - Gertrude Stein New Users:Read This First
Open Source Security Myths Dispelled Dispel the five major myths surrounding Open Source Security and gain the tools necessary to make a truly informed decision for your IT organization subscribe
InformationWeek InformationWeek is the only newsweekly you'll need to stay on top of the latest developments in information technology. subscribe
Gentoo Linux Help For help and discussion related to Gentoo Linux
Submit Your Article
Latest Articles
Editor's Choice
Article Categories
Join Linux Forums Today
Win Great Prizes
windows on one disk, linux on the other. I'll post what you want in about an hour. Cheers.
Linear Mode
