first off, are you sure its not running by checking the following commands;
You can check that the ldap is actually running by using the command
netstat -lntp | grep 389 and it should show something like this;
# netstat -lntp | grep 389
tcp 0 0 0.0.0.0:389 0.0.0.0:* LISTEN 28783/slapd
tcp 0 0 :::389 :::* LISTEN 28783/slapd
If it is not running then try and start the command from the command line (so you can see any error messages to standard outout/error) like so;
# /usr/sbin/slapd -d 1
@(#) $OpenLDAP: slapd 2.3.43 (Feb 22 2012 15:59:04) $
daemon_init: listen on ldap:///
daemon_init: 1 listeners to open...
my log file seems to be located by default in
/var/log/slapd.log , so that is the first place to look for additional information.
If it is definitely not starting, then you can edit the
/etc/openldap/slapd.conf file to increase the logging activity with the loglevel command;