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... -- Best Regards, Giles Coochey NetSecSpec Ltd NL T-Systems Mobile: +31 681 265 086 NL Mobile: +31 626 508 131 GIB Mobile: +350 5401 6693 Email/MSN/Live Messenger: giles at coochey.net Skype: gilescoochey -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/pkcs7-signature Size: 5137 bytes Desc: S/MIME Cryptographic Signature URL: <http://lists.centos.org/pipermail/centos/attachments/20110203/fe09f26b/attachment-0005.p7s>