[CentOS] Lost root access
Rafa Grimán
rafagriman at gmail.com
Thu Feb 3 19:12:17 UTC 2011
Hi :)
On Thursday 03 February 2011 14:59 Giles Coochey wrote
> On 03/02/2011 14:40, Rafa Griman wrote:
> > Hi :)
> >
> > On Wed, Feb 2, 2011 at 3:44 PM, James Bensley<jwbensley at gmail.com> wrote:
> >> So on a virtual server the root password was no longer working (as in
> >> I couldn't ssh in anymore). Only I and one other know it and neither
> >> of us have changed it. No other account had the correct privileges to
> >> correct this so I'm wondering, if I had mounted that vdi as a
> >> secondary device on another VM, browsed the file system and delete
> >> /etc/shadow would this have wiped all users passwords meaning I could
> >> regain access again?
> >>
> >> (This is past tense because its sorted now but I'm curious if this
> >> would have worked? And if not, what could I have done?).
> >
> > As the other said: DON'T delete /etc/shadow.
> >
> > Someone also mentioned you could modify the hash in /etc/shadow. This
> > will work if you are root or have the right permissions with sudo.
> >
> > If you can reboot the system, what really works great is passing the
> > following option to the kernel on the lilo/grub screen when the system
> >
> > boots:
> > init=/bin/bash
> >
> > This will give you a shell without being asked for a password (unless
> > the sys admin has done his homework ;) Now that you have shell access
> >
> > ... you are in charge so you can:
> > - mount the / partition and chroot
> >
> > - edit /etc/shadow and delete the password hash
> >
> > - whatever you can imagine ... you decide ;)
>
> That would do it... There is single-user-mode (runlevel 1), just add the
> word single to the kernel parameters line before bootup
>
> It will give you the same result and mount stuff without the need to
> chroot etc...
Yes, but S|Single|1 asks for root password to login ... And he doesn't have
the root password ;)
Rafa
--
"We cannot treat computers as Humans. Computers need love."
Happily using KDE 4.5.5 :)
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