[Solved] Reset root password

wickyd · 2009-03-17 14:09:00

Hi folx

I need to reset the root password. I tried going into GRUB and appending the relevant line with:

(1.) single
(2.) 1
(3.) single init=/bin/bash

Result:
(1.) asked for root password during boot
(2.) asked for root password during boot
(3.) didn't get that far as it went into kernel panic

I downloaded Ubuntu 8.10 desktop to use as a live CD, but that didn't work as the CD just dumped me into an initramfs session.

How am I supposed to reset my root password?

Thank you, wickyd.

Last edited by wickyd (2009-03-19 07:38:14)

Allan · 2009-03-17 14:15:03

See tip #4 on this page. http://www.ibm.com/developerworks/linux … 9&S_CMP=GR

lilith2k3 · 2009-03-17 14:41:50

chose another live-Distro (e.g. knoppix)
chroot into your system an use

passwd

as usual

wickyd · 2009-03-17 14:55:44

Allan: Thanks but this is exactly my point .. the tips suggested there don't work for Arch Linux.

I never get to a bash shell because Arch asks me for the root password before I can enter single user mode.

lilith2k3: I don't think that will solve the problem as this is very old hardware. I couldn't even install from CD, I had to install via FTP.

Is there any other way to do this?

Procyon · 2009-03-17 15:10:04

How about using an editor instead. init=/usr/bin/nano?

Ghost1227 · 2009-03-17 15:28:44

if you can boot from a cd, try a minimal cd like the LFS live cd or DSL... if not, maybe a USB drive image?

Procyon · 2009-03-17 15:46:27

Use a floppy distro.

wickyd · 2009-03-17 16:36:30

Procyon: This looks very promising, but something isn't working ...

These are the steps I took:

1. Change grub kernel line from ro to rw (or else nano can't write files) and append single init=/usr/bin/nano.
2. nano loads successfully.
3. edit /etc/shadow and remove root password.
4. reboot server and attempt to login, but server claims the login is incorrect.
5. reboot again into nano and discover /etc/shadow is 0k in size.

Repeat steps above with the same result.

Any idea what is going wrong?

Procyon · 2009-03-17 17:22:22

Completely empty? Did you remove the field after the password too? (there is a days since 1970 field right after it) Maybe completely clearing the shadow file is a result of an invalid entry.

Procyon · 2009-03-17 18:15:30

This looks interesting: http://www.cyberciti.biz/tips/recoverin … -file.html

Maybe you can use init=/usr/sbin/pwconv

SkonesMickLoud · 2009-03-17 18:36:17

Silly question, I know, but do you have sudo permission?

You can reset the root password with your user password, if you've got sudo access.

wickyd · 2009-03-18 06:28:50

Procyon: Yes, it is completely empty. I copy the file shadow- (backup file) to shadow which ends up being 145bytes after editing. However, once I reboot the file is 0bytes. It is as if the write is not permanent.

Procyon: Thank you again for that link, unfortunately that link assumes that init=/bin/bash works but my machine goes into kernel panic when I append that.

Can someone else please confirm if appending single init=/bin/bash works for them.

Is it peculiar to my hardware or do other people also experience a kernel panic while trying that route?

SkonesMickLoud: I know that would seem the obvious route, but I can't use Sudo to fix the problem.

Procyon · 2009-03-18 09:08:39

I see, then the pwconv won't make a difference.

When you do init=/usr/bin/nano, what happens when you quit nano?

Maybe you need to force sync the hard drive using alt+sysrq+s (after you enabled it) or opening /proc/sysrq-trigger with nano, and writing s to it.

BTW if you use vim, can you do :! bash?

moljac024 · 2009-03-18 11:31:03

What about single user mode ?
When you get to grub, press e to edit an entry, select the kernel line, press e again and append the word single and then press b to boot. Hopefully that should get you to a root prompt so you can reset the password.

Last edited by moljac024 (2009-03-18 11:34:34)

bluewind · 2009-03-18 12:47:41

moljac024 wrote:

What about single user mode ?
When you get to grub, press e to edit an entry, select the kernel line, press e again and append the word single and then press b to boot. Hopefully that should get you to a root prompt so you can reset the password.

But you did read his first post, didn't you?

SiC · 2009-03-18 13:58:02

Easiest way would be to download either the USB image for Arch, or the LiveCD.

Boot from it.

Mount your root partition at say /mnt/root.

chroot into it using chroot /mnt/arch /bin/bash

run passwd.

Your root password should now be reset. Hopefully.

Hrod beraht · 2009-03-18 14:19:46

I used the procedure in the wiki: Password Recovery.

Bob

perbh · 2009-03-18 14:25:46

http://bbs.archlinux.org/viewtopic.php?id=66906

Procyon · 2009-03-18 14:38:48

init=/usr/bin/passwd?

Procyon · 2009-03-18 14:44:22

Is it possible you edited the /etc/shadow of the initrd?

quarkup · 2009-03-18 14:50:38

-> if you are using an ext2 or 3 (or 4 maybe) or reiserfs

-> if you're dual-booting with windows, there are apps to access the partition/disk with the linux os. access it then change it.

Napaim · 2009-03-18 16:28:04

I'd have thought a usb boot + chroot or mounting the arch fs would work.

perbh · 2009-03-18 16:46:45

this has all been discussed before - ad nauseatum

1) boot up with _any_ live cd
2) mount your root filesystem as - say - /mnt/fs
3) vi /mnt/fs/etc/passwd
change the first line to:
root::0:0:root:/root:/bin/bash
4) unmount /mnt/fs and reboot
5) you can now log in as 'root' with no passwd
6) pwconv && passwd (now set new password)

<edit>
With all due respect - chroot is _not_ the way to go.
In order to actually _set_ a new password, you have to run the same kind of
authorization as in your present system - it may be different for different distros.
</edit>

Last edited by perbh (2009-03-18 16:49:01)

xd-0 · 2009-03-18 17:07:00

Try to use init=/bin/bash and run single user mode.

moljac024 · 2009-03-18 21:21:12

bluewind wrote:

moljac024 wrote:
What about single user mode ?
When you get to grub, press e to edit an entry, select the kernel line, press e again and append the word single and then press b to boot. Hopefully that should get you to a root prompt so you can reset the password.
But you did read his first post, didn't you?

Ooops..

Arch Linux

#1 2009-03-17 14:09:00

[Solved] Reset root password

#2 2009-03-17 14:15:03

Re: [Solved] Reset root password

#3 2009-03-17 14:41:50

Re: [Solved] Reset root password

#4 2009-03-17 14:55:44

Re: [Solved] Reset root password

#5 2009-03-17 15:10:04

Re: [Solved] Reset root password

#6 2009-03-17 15:28:44

Re: [Solved] Reset root password

#7 2009-03-17 15:46:27

Re: [Solved] Reset root password

#8 2009-03-17 16:36:30

Re: [Solved] Reset root password

#9 2009-03-17 17:22:22

Re: [Solved] Reset root password

#10 2009-03-17 18:15:30

Re: [Solved] Reset root password

#11 2009-03-17 18:36:17

Re: [Solved] Reset root password

#12 2009-03-18 06:28:50

Re: [Solved] Reset root password

#13 2009-03-18 09:08:39

Re: [Solved] Reset root password

#14 2009-03-18 11:31:03

Re: [Solved] Reset root password

#15 2009-03-18 12:47:41

Re: [Solved] Reset root password

#16 2009-03-18 13:58:02

Re: [Solved] Reset root password

#17 2009-03-18 14:19:46

Re: [Solved] Reset root password

#18 2009-03-18 14:25:46

Re: [Solved] Reset root password

#19 2009-03-18 14:38:48

Re: [Solved] Reset root password

#20 2009-03-18 14:44:22

Re: [Solved] Reset root password

#21 2009-03-18 14:50:38

Re: [Solved] Reset root password

#22 2009-03-18 16:28:04

Re: [Solved] Reset root password

#23 2009-03-18 16:46:45

Re: [Solved] Reset root password

#24 2009-03-18 17:07:00

Re: [Solved] Reset root password

#25 2009-03-18 21:21:12

Re: [Solved] Reset root password

Board footer