Hi,
I'm posting this mostly for the archives, so that a search for the error below will help a next person.
Today I wanted to setup the cn=Monitor backend, and after doing so, openldap failed to start with:
backend_startup_one (type=monitor, suffix="cn=Monitor"): bi_db_open failed! (-1)
The reason turned out to be: we had configured one of our databases ("database ldap") without a suffix.
After I added a suffix, openldap started, and cn=Monitor worked as expected.
I added a simple placeholder suffix (o=ldap,c=com) and now I need to find out what the database ldap was actually used for in our setup, and what the proper suffix should be. (does anyone perhaps know what openldap used as a default, if a "database ldap" suffix is omitted from the config?)
Anyway: Hopefully this post will help a future someone with the same error message, as the error message had little to do the the cause.