Alibaba Cloud ECS Ubuntu Forgets Root Password Solution

This method only applies if the root password cannot be changed through the ECS console

Check the/etc/default/grub

cat /etc/default/grub

Modify /etc/default/grub

sed -i 's/GRUB_HIDDEN_TIMEOUT=0/#GRUB_HIDDEN_TIMEOUT=0/g' /etc/default/grub
sed -i 's/GRUB_TIMEOUT=30/GRUB_TIMEOUT=50/g' /etc/default/grub
sed -i 's/GRUB_HIDDEN_TIMEOUT_QUIET=true/GRUB_HIDDEN_TIMEOUT_QUIET=false/g' /etc/default/grub

Check to see if the modification was successful

update /etc/default/grub

sudo update-grub

Force a restart at the ECS console to open a VNC window using the remote connection to the ECS console, VNC

To move to advanced mode press e

Follow the screenshot below

Modify RO Recovery Nomodese into Quiet Splash RW init=/bin/bash

Press F10

To select the recovery mode, press E

Modify RO Recovery Nomodese into Quiet Splash RW init=/bin/bash

Press F10

Change the password

Enter a new password

Restart the system at the ECS console