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.

Set Up Your VPS

To access the live rescue image more easily, verify that you are using "pv-grub", using the Management Console. Check option 9.

Name                                        ID   Mem VCPUs	State	Time(s)
cnryfield                                  218  1024     1     r-----    1898.8

    Wiki at http://wiki.prgmr.com
    Please contact support@prgmr.com with any issues accessing your machine.

    Options for "cnryfield"
    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 "i386"
    7. view/add/remove ssh authorized_keys
    8. set reverse dns
    9. swap pvgrub/grub2 bootloaders currently "pv-grub"

    0. exit
    enter selection> 

If the current bootloader is grub2, press 9 to switch to pv-grub.

Check whether you are running in 32 bit (i386) or 64 bit (amd64) mode by looking at option 6:

6. swap i386/amd64 bootloaders currently "i386"

and switch if desired.

Reset Your Password

1. If the vps (domain) is still running, enter option 3 to shut it down safely.

   When the machine is stopped, the Management Console menu will return. Pressing Enter will generate a new menu with a different heading:

Domain 'cnryfield' is not running.

2. Choose option 2 (create/start) to start the vps.

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

GNU GRUB  version 0.97  (131072K lower / 0K upper memory)
 +-------------------------------------------------------------------------+
 | user bootloader configuration                                           |  
 | Debian GNU/Linux, kernel 3.2.0-4-amd64 Live Rescue                      |
 | Debian GNU/Linux, kernel 3.2.0-4-amd64 (single-user mode) Live Rescue   |
 | ubuntu-trusty-14.04-64 rescue                                           |
 | ubuntu-trusty-14.04-64 install                                          |
 | centos5-64 rescue                                                       |
 | centos5-64 install                                                      |
 | debian-wheezy-7.0-64 rescue                                             |
 | debian-wheezy-7.0-64 install                                            |
 | fedora20-64 rescue                                                      |
 | fedora20-64 install                                                     |
 | centos6-64 rescue                                                       | v
 +-------------------------------------------------------------------------+
    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 Debian GNU/Linux Live Rescue to boot the read only rescue image. When it is finished booting, log in as root at the prompt with no password:

Debian GNU/Linux 8 rescue hvc0

rescue login: root
Linux rescue 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt20-1+deb8u3 (2016-01-17) x86_64
Documentation on installing a new image is at 
http://wiki.prgmr.com/mediawiki/index.php/Untarring_a_fresh_OS_image

To enable ssh access to the rescue image, copy
your public key to /root/.ssh/authorized_keys and type
"service ssh start"
root@rescue:~#

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

root@rescue:~# mount /dev/xvda1 /mnt
[  330.620031] EXT4-fs (xvda1): mounting ext3 file system using the ext4 subsystem
[  330.689992] EXT4-fs (xvda1): mounted filesystem with ordered data mode. Opts: (null)
root@rescue:~# chroot /mnt
[root@rescue /]# 

5. Change the root password with passwd:

[root@rescue /]# passwd
Enter new UNIX password: 
Retype new UNIX password: 
passwd: password updated successfully
[root@rescue /]# 

6. Exit, unmount, and shutdown:

[root@rescue /]# exit
exit
root@rescue:~# umount /mnt
root@rescue:~# shutdown -h now
         Starting Synchronise Hardware Clock to System Clock...

7. This will return you to the Management Console. Start the domain again as in step 2, but let it load the "user bootloader configuration" instead of choosing the rescue image.