Hey !!! On Thursday 03 February 2011 20:42 Robert Heller wrote > At Thu, 3 Feb 2011 20:12:17 +0100 CentOS mailing list <centos at centos.org> wrote: > > 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 ;) > > RedHat / RHEL / CentOS does not do that! True, just tried it with RHEL 6 and CentOS 5.3. Well it should ask for a passwd ... at least IMHO. Then again ... an admin should configure grub/lilo to ask for a password if you pass parameters to the kernel during boot time :) > At least never on any of my > machines -- is there some config option for that? Yes, for manual fchk > it does, but not otherwise. I'll check, but no idea. Rafa -- "We cannot treat computers as Humans. Computers need love." Happily using KDE 4.5.5 :)