[SOLVED] unable determine major/minor number of root device 'dev/sda6'

miky76 · 2012-02-11 19:06:14

Hi,
today I've upgraded the pacman package to the 4.0x version. (the one with the keys)

I've rebooted and anything was ok.

than I've launched the command

pacman -Syu

and the upgrade of around 140 packages started smoothly

after it finished, i made a reboot, and the error in the subject appear:

ERROR: unable to determine major/minor number of root device 'dev/sda6'

if I try the fallback one, I do not see any changes.

what do I have to do?

I've read many posts where the solution is use the installation CD, but I cannot do it, because I do not have any CD hole in my box.

can you help me?

Last edited by miky76 (2012-03-21 12:13:35)

/dev/zero · 2012-02-11 20:28:07

miky76 wrote:

I've read many posts where the solution is use the installation CD, but I cannot do it, because I do not have any CD hole in my box.

Can you boot from USB?

fsckd · 2012-02-11 21:00:21

Hello miky76, you accidentally sent your post to the moderators via report. Don't worry, it happens to someone every now and then.

miky76 wrote:

yes I can, but I'm not sure how can i do it... I'm quite new in linux
but if you tell me step by step I can make it

@ about 10 minutes ago.

miky76 · 2012-02-11 22:07:14

I told you I'm new in linux (and in linux forums)

just a joke

/dev/zero · 2012-02-11 22:15:59

miky76 wrote:

yes I can, but I'm not sure how can i do it... I'm quite new in linux
but if you tell me step by step I can make it

By the oracular powers of the Wiki, I present to you: How to make a bootable Archlinux USB

miky76 · 2012-02-11 22:17:52

hehehe I liked the joke!!

I will check it and come back to you

thanks for now!

miky76 · 2012-02-17 22:08:46

seem Incredible but I've made to boot from USB...

only one thing is not really clear to me...

at the end it says

---------------------------------------------------
After booting from the USB stick:

Start the installation by logging in as root and invoke the command "/arch/setup".

The installer should mount the source media automatically. If it fails you can manually mount the source media on the stick to the /src directory with the following command:
mount /dev/sd[x] /src
------------------------------------------------

I type /arch/setup, and it ask me what I would like to do... and nothing is really so automatic

I've checked here https://wiki.archlinux.org/index.php/Of … tion_Guide but seem everything is for install a NEW arch not to fix the broken one...

/dev/zero tell me the next step!!

miky76 · 2012-02-21 16:16:06

Hi,
do you think the chroot will help me with this?

https://wiki.archlinux.org/index.php/Change_Root

i'm not so sure..

nomorewindows · 2012-02-21 18:25:17

miky76 wrote:

Hi,
do you think the chroot will help me with this?
https://wiki.archlinux.org/index.php/Change_Root
i'm not so sure..

You still have to mount your partitions first before using chroot and in the correct order on top of the common structure (usually /mnt).
Usually an error of this nature is either missing linkage in the initramfs image, or missing a needed hook in /etc/mkinitcpio.conf or the image didn't compile or was aborted in the process. You really shouldn't need /arch/setup unless you need it to activiate your network card or something else embedded in the installer. Most likely you need to mount your /, and /boot, but with the additon of kmod /usr if it is separate, and then with the correct hooks in mkinitcpio, chroot, and run mkinitcpio.

Last edited by nomorewindows (2012-02-21 18:25:55)

miky76 · 2012-02-23 22:33:53

hi All

with fdisk -l I foud out that my USB where the broken OS is, is called sdd1

so I'm mounted it in mnt/arch dir

I followed all the steps here
https://wiki.archlinux.org/index.php/Change_Root

till the command

chroot . /bin/bash

and as stated in the wiki i get the error:

Wiki wrote:

If you see the error, "chroot: cannot run command '/bin/bash': Exec format error" it is likely the two architectures do not match.

but I do not find solution for it.
Both the USB OS and the not working one are ArchLinux, so I'm puzzle and I do not know what to do

thanks

/dev/zero · 2012-02-23 23:05:34

miky76 wrote:

hi All
Wiki wrote:
If you see the error, "chroot: cannot run command '/bin/bash': Exec format error" it is likely the two architectures do not match.
but I do not find solution for it.
Both the USB OS and the not working one are ArchLinux, so I'm puzzle and I do not know what to do
thanks

The architecture I think refers to whether you're running a 32-bit or 64-bit kernel. For example, if you've installed 32-bit ArchLinux on your usb, and 64-bit on your hard-drive, this would explain an architecture mismatch. It does say at the top of the chroot how-to:

The Archlinux Wiki wrote:

Be sure that the architectures of the Linux environment you have booted into matches the architecture of the root directory you wish to enter (i.e. i686, x86_64).

I tried stfwing to see whether it is possible to work around this constraint, and did not see any instructions for you to follow.

The simplest thing at this juncture is for you to re-create your usb and this time make sure the architecture matches.

miky76 · 2012-02-26 21:31:28

OK!

I've booted with a new 64bit OS on USB

and I did chroot successfully, but I'm not sure not what should I do next

I've checked in the fstab and seem that only the tmpfs is there

in the grub, ne menu.lst has the following entry

(0) Arch linux
root (hd0,0)
kernel /vmlinuz-linux root=/dev/sda3 ro
initrd /initramfs-linux.img

i'm not sure about this sda3 entry, do you think it is ok?

thanks

/dev/zero · 2012-02-26 22:42:28

miky76 wrote:

I've checked in the fstab and seem that only the tmpfs is there

It seems weird that your fstab doesn't have anything. Are you sure there's nothing else in there?

miky76 wrote:

in the grub, ne menu.lst has the following entry
(0) Arch linux
root (hd0,0)
kernel /vmlinuz-linux root=/dev/sda3 ro
initrd /initramfs-linux.img
i'm not sure about this sda3 entry, do you think it is ok?

The initial error said there was a problem with /dev/sda6, so this does seem a little odd.

If we ask you to run commands inside the chroot environment, do you have a way to get the output to the forum? For example, do you have another computer you can ssh to?

miky76 · 2012-02-26 23:29:51

I have another PC and usually I ssh to the linux one, but at the moment, seem the linux doesn't recognize the network, so if I run ifconfig the inet addr is 127.0.0.1 and I'm not sure how I can make it work with chroot on.

I can run the command you want me to run, and copy the result in this forum by hands, if you want.

I confirm you the only line present in fstab is the one with tmpfs, it seem strange even to me....

p.s. I've modified the menu.lst changing sda3 in sda6 in the root=/dev/sda3, rebooted, but no luck!!

/dev/zero · 2012-02-26 23:46:26

miky76 wrote:

I can run the command you want me to run, and copy the result in this forum by hands, if you want.

Okay, inside the chroot run:

sudo fdisk -l /dev/sda

grep -i -C3 linux /boot/grub/menu.lst

grep "^MODULES\|^HOOKS" /etc/mkinitcpio.conf

The first command will list all the partitions on /dev/sda. The second should output all your grub entries - I know you already did this, but please humour me. The third will show the modules and hooks which should be in your initramfs.

Please remember to put each lot of output in a separate code block.

miky76 · 2012-02-26 23:49:37

maybe I do something wrong before arrive to the chroot

when I do chroot . bin/bash
do I have to be in the root folder or in the /mnt (where I've mounted the broken OS?) I'm not sure I did on the right one

ewaller · 2012-02-27 00:11:05

By using '.' you are passing the current directory info the chroot. The current directory becomes the root of your chroot. You want to be in the mount point where your broken OS is mounted. Or, issue the command as chroot <full path to mount point> /bin/bash . Also, I think you should use /bin/bash, not bin/bash. Your form will probably work, but I like to be explicit.

miky76 · 2012-02-27 08:13:41

I've tryied to do

cd\
chroot /mnt/arch/bin/bash

but I get the erro message "cannot change root /mnt/arch/bin/bash: in not a directory"

then I did:

cd /mnt/arch
chroot . /bin/bash

but as before the fstab still have only the tmpfs line.

I agree with you, I think that this fstab is the one of the booting OS and not of the one I'm looking for

miky76 · 2012-02-29 00:06:25

I'm trying and trying but I cannot make the chroot see the fstab of the broken OS, and not of the booting one

can you give me a hint?

I've mounted the broken OS on the /mnt/arch dir

thanks

nomorewindows · 2012-02-29 14:34:26

miky76 wrote:

I've tryied to do
cd\
chroot /mnt/arch/bin/bash
but I get the erro message "cannot change root /mnt/arch/bin/bash: in not a directory"
then I did:
cd /mnt/arch
chroot . /bin/bash
but as before the fstab still have only the tmpfs line.
I agree with you, I think that this fstab is the one of the booting OS and not of the one I'm looking for

/mnt is usually free and clear of any other directories and only containing that which is mounted.
/mnt doesn't care whether you are mounting windows, linux, or some secret little OS we've never heard of.
/mnt/arch is ambiguous, and maybe confusing the issue.
You can look at your /etc/fstab outside of the chroot, by calling /mnt/.../etc/fstab instead, assuming you are mounted.
chroot /mnt/.../bin/bash is trying to mount the binary, correct this by cd / ;chroot /mnt/... /bin/bash (space needed) or just simply cd /; chroot /mnt/...

miky76 · 2012-02-29 20:39:45

ok, let start from scratch

- started the OS from new usb
- mounted the old OS in /mnt/oldarch

vi /mnt/oldarch/etc/fstab

it shows 6 line

/dev/data/databin    /data ext4  defaults 0 1
/dev/sda1      /boot    ext2  defaults 0 1
/dev/sda6     /      ext4   defaults 0 1
/dev/sda5    swap  swap     defaults 0 0
/dev/sdb1   /var/cache/pacman/pkg   ext4     defaults 0 0
tmpfs   /tmp   tmpfs  nodev,nosuid  0  0

this fstab is the one I expect to see!!

then I mount

cd /mnt/arch
mount -t proc proc proc/
mount -t sysfs sys sys/
mount -o bind /dev dev/
mount -o bind /boot boot/
mount -o bind /var var/
mount -o bind /usr usr/

mount /dev/sdd1 boot/

now the chroot

cd / ;chroot /mnt/... /bin/bash

checking the fstab now I can see the right one!!!

/dev/zero wrote:

Okay, inside the chroot run:

sudo fdisk -l /dev/sda

grep -i -C3 linux /boot/grub/menu.lst

grep "^MODULES\|^HOOKS" /etc/mkinitcpio.conf

sudo is not recognized so I dis:

fdisk -l /dev/sda

result:

Disk /dev/sda: 1000.2 GB, 1000etc bytes
and some technical details (heads, sectors, cylinders, etc....

Device Boot: /dev/sda1
Start: 1
end: 1953525167
block: a big number
Id: ee
System: GPT

grep -i -C3 linux /boot/grub/menu.lst

it return 4 entry:

#(0) Arch Linux
title Arch Linux
root (hd0,0)
kernel /vmlinuz-linux root=/dev/sda6 ro acpi_enforce_resources=lax
initrd /initramfs-linux.img

#(1) Arch Linux
title Arch Linux Fallback
root (hd0,0)
kernel /vmlinuz-linux root=/dev/sda6 ro 
initrd /initramfs-linux-fallback.img

#(2) Arch Linux USB
title Arch Linux USB
root (hd0,0)
kernel /vmlinuz-linux root=/dev/sda6 ro 
initrd /initramfs-linux-usb.img

#(3) Windows
title Windows

I remeber Ive changed in the (0) the root from sda3 to sda6 for try to make it work again

the (2) it's an old not working arch linux, that I would like to remove one day

the third command

grep "^MODULES\|^HOOKS" /etc/mkinitcpio.conf

MODULES="ext2 dm_mod"
HOOKS="base udev usb lvm2 mdadm autodetect pata scsi sata filesystems usbinput"

hope this will help for fix it

Last edited by miky76 (2012-02-29 20:40:45)

falconindy · 2012-02-29 23:26:58

Please post your pacman.log from the broken system. You can use a command line pastebin tool like sprunge...

curl -sF "sprunge=</var/log/pacman.log" 'http://sprunge.us'

miky76 · 2012-03-01 20:16:30

the command you gave me doesn't do anything because I do not have the network working,

ifconfig say that my ip is 127.0.0.1
I've tryed to restart network, but it's not working I do not know why

anyway,

my pacman.log file say only one thing

[yesterday date] Running 'pacman -Syu nano'
[yesterday date] syncronizing package lists

I think, that when I've tryied to install nano yesterday it deleted the previous log, but I do not see and older pacman.log file in the log dir not even in the old one

I've checked all my logs, and seem that all of them start from Feb 29 12:01:08 (when I believe, I've rebooted and chrooted), nothing is earlier than this date and time

before, the crash, I've updated to the new pacman (the one with the keys), updated the keys and upgraded something like 140 packages, one of them was the linux 3.0.3-1 (can it be this one the problem?)

miky76 · 2012-03-01 20:32:44

i've tryed

exit
cp -L /etc/resolve.conf /mnt/oldarch/etc/resolve.conf
cd / ;chroot /mnt/... /bin/bash
/etc/rc.d/network restart

and the network is working now, as I can ping google.com

but I can not connect with another pc through ssh to this one as I usually do... I do not know why

p.s. che command

curl -sF "sprunge=</var/log/pacman.log" 'http://sprunge.us'

doesn't give me error nor return anything, what do you expect from it?

miky76 · 2012-03-01 20:58:26

now I did

/etc/rc.d/sshd restart

the message say FAIL

Starting Secure Shell Daemon  [BUSY]
ssh-keygen: illegal option -- A
usage: ssh-keygen [options]
Options:
  here is written a long list of options

when I try to connect with ssh from another pc:

login as: root
root@10.100.100.94's password:
Server refused to allocate pty

Arch Linux

#1 2012-02-11 19:06:14

[SOLVED] unable determine major/minor number of root device 'dev/sda6'

#2 2012-02-11 20:28:07

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#3 2012-02-11 21:00:21

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#4 2012-02-11 22:07:14

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#5 2012-02-11 22:15:59

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#6 2012-02-11 22:17:52

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#7 2012-02-17 22:08:46

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#8 2012-02-21 16:16:06

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#9 2012-02-21 18:25:17

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#10 2012-02-23 22:33:53

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#11 2012-02-23 23:05:34

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#12 2012-02-26 21:31:28

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#13 2012-02-26 22:42:28

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#14 2012-02-26 23:29:51

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#15 2012-02-26 23:46:26

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#16 2012-02-26 23:49:37

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#17 2012-02-27 00:11:05

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#18 2012-02-27 08:13:41

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#19 2012-02-29 00:06:25

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#20 2012-02-29 14:34:26

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#21 2012-02-29 20:39:45

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#22 2012-02-29 23:26:58

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#23 2012-03-01 20:16:30

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#24 2012-03-01 20:32:44

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

#25 2012-03-01 20:58:26

Re: [SOLVED] unable determine major/minor number of root device 'dev/sda6'

Board footer