Login incorrect debian, how to restore access?

Question

linux

Hello.
The former admin set up Debian for telephony, left a login and password. According to him, they are correct.
But when I try to log in, it says login incorrect.
How can I reset the password and restore access without disrupting the system?
If it's important, debian is up on a virtual machine.

Answer 1

If there is access to the console of the virtual machine - boot into single or emergency (unless, of course, the hornbeam is not password-protected), change the password.
If the grab is password-protected - booting from any LiveCD, mounting disks, demolishing the root password, fucking demolishing the password in the grab. Booting from LiveCD will work even when the hornbeam is not password-protected - it will just be a little less work :)

Answer 2

If this is not a virtual machine, but a container, then you can log into it from the host machine without a password (using commands like vzctl-enter or lxc-attach, depending on the type of containerization)