Root Password Reset

The prgmr.com rescue image can be used to reset the root password for the vps similar to a rescue disk like tomsrtbt or the debian installer rescue mode. If you run netbsd, you can also boot the netbsd installer from the rescue disk for a similar process.

1. If the vps (domain) is still running, shut it down using the Management Console.

   Name                                        ID   Mem VCPUs	State	Time(s)
   cnrylefanu                                 159   256     1     -b----     131.6
   
       Wiki at http://wiki.prgmr.com
       Please contact support@prgmr.com with any issues accessing your machine.
   
       Options for "cnrylefanu"
       1. out of band console (press ctrl-] to escape, not resizeable)
       2. create/start, opens OOB console (try this if the machine is not running)
       3. shutdown (requests operating system to shut down)
       4. force power off (destroy/hard shutdown)
       5. reboot (requests operating system to reboot)
       6. swap i386/amd64 bootloaders currently "amd64"
       7. view/add/remove ssh authorized_keys
       8. set reverse dns
       9. swap pvgrub/grub2 bootloaders currently "pv-grub"
   
       0. exit
       enter selection> 3
   
   

   This will signal the domain to safely shutdown like the shutdown command.
2. When it is stopped running, opening the menu will say

   Error: Domain 'build' does not exist.
   

   which is normal, it just means the vps isn't running. Choose create to start the vps:

   
   Error: Domain 'build' does not exist.                                     
                                                                             
                                                                             
   Options for build                                                         
   1. out of band console (press ctrl-] to escape, not resizeable)
   2. create/start (try this if the vps "does not exist")
   3. shutdown
   4. destroy/hard shutdown
   5. reboot
   6. swap i386/amd64 bootloaders (pvgrub) currently i386
   7. view/add/remove ssh authorized_keys
   8. set reverse dns
   9. exit
   press the number> 2     
   

   The domain will start booting with pvgrub and will load the grub menu from the rescue image:

       
       GNU GRUB  version 0.97  (1048576K lower / 0K upper memory)
    
    +-------------------------------------------------------------------------+
    | user bootloader configuration                                           |  
    | CentOS 5.5 rescue (2.6.18-194.3.1.el5xen)                               |
    | CentOS 5.5 installer                                                    |
    | Ubuntu 10.04 LTS installer                                              |
    |                                                                         |
    |                                                                         |
    |                                                                         |
    |                                                                         |
    |                                                                         |
    |                                                                         |
    |                                                                         |
    |                                                                         |
    +-------------------------------------------------------------------------+
       Use the ^ and v keys to select which entry is highlighted.
       Press enter to boot the selected OS, 'e' to edit the
       commands before booting, or 'c' for a command-line.
   

3. Choose CentOS rescue to boot the read only rescue image. When it is finished booting, login as root at the prompt with no password:

   CentOS release 5.4 (Final)
   Kernel 2.6.18-164.6.1.el5xen on an x86_64
   
   build.xen.prgmr.com login: root
   [root@build ~]#
   

4. Mount your root filesystem (by default /dev/xvda1) and chroot to it:

   [root@build ~]# mount /dev/xvda1 /mnt
   [root@build ~]# chroot /mnt
   build:/#
   

5. Change the root password with passwd:

   build:/# passwd
   Enter new UNIX password: 
   Retype new UNIX password: 
   passwd: password updated successfully
   build:/#
   

6. Exit, unmount, and shutdown:

   build:/# exit
   exit
   [root@build ~]# umount /mnt
   [root@build ~]# shutdown -h now
   
   Broadcast message from root (xvc0) (Tue Jan 26 15:33:15 2010):
   
   The system is going down for system halt NOW!
   INIT: Switching to runlevel: 0
   INIT: Sending processes the TERM signal
   

7. Start the domain again as in step 2, but let it load the "user bootloader configuration" instead of choosing the rescue image.