Our Fedora Core 5 server (arwen) got rather stuck today after a hard restart and failing to reboot. It kept getting stuck on Starting System Message Bus. A bit of googling later and it seemed that the problem originated from the server’s authentication settings.

Several days ago I had been fiddling with the server’s authentication settings (via the gui interface) hoping that it might be able to authenticate against its own ldap directory and had just left the settings sitting there when nothing seemed to be happening. Clearly it was a very bad idea and I should have left it alone.

As per the various posts on FedoraForum I used the following procedure.

Persuade the server to boot into runlevel 1:
push e when grub comes up, then e the 2nd line, add a 1 to the end of the line

Edit /etc/nsswitch.conf
Removing the references to ldap so;
passwd: files ldap
becomes
passwd: files

Edit /etc/sysconfig/authconfig
Changing USELDAP=yes to USELDAP=no.

With this done the system booted properly – however the story was not over as the instance of OpenLDAP itself complained about the database being corrupted.

This was fixed very swiftly using a recipe from Harold’s technotes:

# /usr/sbin/slapd_db_recover -v -h /var/lib/ldap
# service start ldap

With that done the whole thing was behaving properly again. Phew.