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Re: how to change root passwd (if forgotten)



On Thu, 11 Aug 2011 10:23:17 -0400, Nico Kadel-Garcia wrote:

> On Wed, Aug 10, 2011 at 11:25 AM, abdelkader belahcene
> <abelahcene@gmail.com> wrote:
>> Hi,
>> I ve forgotten my root passwd on centos 6 (red hat based),
>>
>> I tried to change it as I used in debian (in debian it works perfectly)
>> , that is:
>>
>> use a cd live (or installation cd1), to access the hd, I mount  my root
>> partition and mount proc and devices
> 
> Definitely the wrong newsgroup, but:
> 
>         * boot with CentOS, RHEL, or Scientific Linux rescue CD * Select
>         "linux rescue" or rescue mode from the CD boot process. * Allow
>         it to mount your old system at /mnt/sysimage with all
> the relevant /dev and /dev/sys utilities under it.
>         * Do "chroot /mnt/sysimage" to enter the environment of the
> mounted directories, in a chroot cage.
>         * THEN do "passwd root"
>         * Exit the chroot. (Just type "exit"). * Sync the disk changes,
>         just as a precaution. (Just type "sync") * Reboot and eject CD.
> 
> I generally setup PXE to make these tools available without a CD in
> large environments,. The "chroot" business is core to updating messed up
> grub configurations, password files, kernels, fstab, or core system
> libraries.
> 
>> I tried  the command passwd, no error reprorted, but after reboot the
>> passwd had´t changed.
>> then I decided to remove passwd from /etc/shadow (delete the second
>> field).
> 
> 
> 
>> OK,  now I can access my machine  without passwd,  BUT I CAN´T GIVE ANY
>> PASSWORD!!!!  I RECEIVE THIS ERROR
>>
>> # passwd
>> Changing password for user root.
>> New password:
>> Retype new password:
>> passwd: Authentication token manipulation error
>>
>> any idea to fix the problem.
>> thanks a lot
>>

All the responses (except one) have me mystified. Why can't OP just boot 
into single user mode?



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