Cannot login at hvc0

Question

Our LDAP server recently crashed and now we are facing problems reaching some of our servers.

We have a Xen guest for which the login does no longer work. In the logs, the following error appears.

FAILED LOGIN (1) on '/dev/hvc0' FOR 'root'

Here's a list of what I already tried (and did not resolve the problem).

• Resetting the root password (mounting to host, chroot and passwd, usual stuff...)
• Adding a new local account with root privileges (edited the sudoers file)
• Access through SSH...

All is broken. There is a MySQL server that is failing on that vm and I would really like to fix it. The vserver runs debian squeeze and hvc0 is listed in /etc/securetty.

I'm out of options... All help is appreciated!

Answer 1

Your PAM configuration may be wrong. Your configuration should be something like this:

auth [success=1 default=ignore] pam_unix.so
auth required pam_ldap.so use_first_pass
auth required pam_permit.so


account [success=1 default=ignore] pam_unix.so
account required pam_ldap.so
account required pam_permit.so

With those lines, local files are checked before LDAP.

Answer 2

I think you face two distinct configuration options that forbids root logins. One is that root login will be allowed (by /sbin/login or PAM configuration) if there is an entry in /etc/securetty file for hvc0 device. Other is that sshd by default forbids login directly to root account.

You should add hvc0 line/item to /etc/securetty file.