error message explanation

[Drenning Bruce]

2.05a on redhat 6.0 w/ security = domain

I'm installing & configuring for the 1st time. Everything seems to be
working but I'm getting an error message in the log files over & over. I
just want to make sure I can continue to disregard it (or prevent it).

The message contains:

passdb/passdb.c:iterate_getsam21pwrid(315) unable to open sam password
database.

As I said, everything appears to be working but I would like to know why
this is being logged.