To reset the root password of your server, you will need to boot into single user mode.
Access the Manage section of your server in the customer portal and follow these steps. The option depends on the bootloader version on the machine:
passwdto change the root password.
mount -o remount,rw /.
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.
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: