Access Single User Mode (Reset Root Password)

Published on: Wed, Sep 17, 2014 at 12:52 pm EST
FAQ Linux Guides

To reset the root password of your server, you will need to boot into single user mode.

Access your server in the Vultr customer portal, then follow the steps below for the operating system installed on your server.

CentOS 6

  1. Click [View Console] to access the console and click the send CTRL+ALT+DEL button on the top right. Alternatively, you can also click [RESTART] to restart the server.
  2. You will see a GRUB boot prompt telling you to press any key - you have only a few seconds to press a key to stop the automated booting process. (If you miss this prompt you will need to restart the VM again)
  3. At the GRUB prompt, type A to append to the boot command.
  4. Add the text single and press ENTER.
  5. The system will boot and you will see the root prompt. Type passwd to change the root-password and then reboot again.

CentOS 7

  1. Click [View Console] to access the console and click the send CTRL+ALT+DEL button on the top right. Alternatively, you can also click [RESTART] to restart the server.
  2. As soon as the boot process starts, press ESC to bring up the GRUB boot prompt. You may need to turn the system off from the control panel and then back on to reach the GRUB boot prompt.
  3. You will see a GRUB boot prompt - press E to edit the first boot option. (If you do not see the GRUB prompt, you may need to press any key to bring it up before the machine boots)
  4. Find the kernel line (it starts with "linux16"), change ro to rw init=/sysroot/bin/sh.
  5. Press CTRL+X or F10 to boot single user mode.
  6. Access the system with the command: chroot /sysroot.
  7. Run passwd to change the root password.
  8. Reboot the system: reboot -f.

CentOS 8

  1. Click [View Console] to access the console and click the send CTRL+ALT+DEL button on the top right. Alternatively, you can also click [RESTART] to restart the server.
  2. As soon as the boot process starts, press ESC to bring up the GRUB boot prompt. You may need to turn the system off from the control panel and then back on to reach the GRUB boot prompt.
  3. You will see a GRUB boot prompt - press E to edit the first boot option. (If you do not see the GRUB prompt, you may need to press any key to bring it up before the machine boots)
  4. Find the kernel line (it starts with "linux"), change ro to rw init=/sysroot/bin/sh.
  5. Press CTRL+X or F10 to boot single user mode.
  6. Access the system with the command: chroot /sysroot.
  7. Run passwd to change the root password.
  8. Run touch /.autorelabel to force file system relabeling.
  9. Run exit.
  10. Run logout.
  11. Reboot the system: reboot.

CoreOS

CoreOS by default uses SSH key authentication. On Vultr, a root user and password are created. If an SSH key is selected when creating the VPS, this SSH key can be used to login as user "core".

It is possible to reset the standard root login by executing sudo passwd as user "core". Login as "core" using the SSH key first.

If you lost your SSH key, then you can login as the "core" user by editing the grub loader. Follow these steps:

  1. Click [View Console] to access the console and click the send CTRL+ALT+DEL button on the top right. Alternatively, you can also click [RESTART] to restart the server.
  2. You will see a GRUB boot prompt - press "E to edit the first boot option. (If you do not see the GRUB prompt, you may need to press any key to bring it up before the machine boots)
  3. At the end of the line that begins with linux$ add coreos.autologin=tty1.
  4. Press CTRL+X or F10 to boot. You will be logged in as "core" when the system boots.
  5. Remember to reboot your server after you have reset your login.

Debian 9, Debian 10

  1. Click [View Console] to access the console and click the send CTRL+ALT+DEL button on the top right. Alternatively, you can also click [RESTART] to restart the server.
  2. As soon as the boot process starts, press ESC to bring up the GRUB boot prompt. You may need to turn the system off from the control panel and then back on to reach the GRUB boot prompt.
  3. You will see a GRUB boot prompt - press E to edit the first boot option. (If you do not see the GRUB prompt, you may need to press any key to bring it up before the machine boots)
  4. Find the kernel line (it starts with linux /boot/) and add init=/bin/bash at the end of the line.
  5. Press CTRL+X or F10 to boot.
  6. The system will boot and you will see the root prompt. Type mount -o remount,rw / and then passwd to change the root password and then reboot again.

Fedora 29 - 31

  1. Click [View Console] to access the console and click the send CTRL+ALT+DEL button on the top right. Alternatively, you can also click [RESTART] to restart the server.
  2. As soon as the boot process starts, press ESC to bring up the GRUB boot prompt. You may need to turn the system off from the control panel and then back on to reach the GRUB boot prompt.
  3. You will see a GRUB boot prompt - press E to edit the first boot option. (If you do not see the GRUB prompt, you may need to press any key to bring it up before the machine boots)
  4. Find the kernel line (it starts with "linux"), change ro to rw init=/sysroot/bin/sh.
  5. Press CTRL+X or F10 to boot single user mode.
  6. Access the system with the command: chroot /sysroot.
  7. Run passwd to change the root password.
  8. Run touch /.autorelabel to force file system relabeling.
  9. Run exit.
  10. Run logout.
  11. Reboot the system: reboot.

FreeBSD 10.x, FreeBSD 11.x, FreeBSD 12.x

The boot menu has an option to boot into single-user mode. Press the key for single user mode 2. At the root prompt, type passwd to change the root password and then reboot again.

OpenBSD 6.x

See "I Forgot My Root Password" in the official FAQ.

Ubuntu 18.xx, Ubuntu 19.xx

  1. Click [View Console] to access the console and click the send CTRL+ALT+DEL button on the top right. Alternatively, you can also click [RESTART] to restart the server.
  2. As soon as the boot process starts, press ESC to bring up the GRUB boot prompt. You may need to turn the system off from the control panel and then back on to reach the GRUB boot prompt.
  3. You will see a GRUB boot prompt - press E to edit the first boot option. (If you do not see the GRUB prompt, you may need to press any key to bring it up before the machine boots)
  4. Find the kernel line (it starts with linux /boot/) and add init=/bin/bash at the end of the line.
  5. Press CTRL+X or F10 to boot.
  6. The system will boot and you will see the root prompt. Type mount -o remount,rw / and then passwd to change the root password and then reboot again.

Windows Server 2012 R2, Windows Server 2016, Windows Server 2019

See Reset Windows Server Administrator Password for instructions on how to reset the administrator password.

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