LDAP 데이터베이스에 항목을 추가할 때 "slapadd: 잘못된 옵션" 발생

내 LDAP 데이터베이스(CentOS 버전 5.11 - LDAP 버전 2.3.43-29.el5_11)에 초기 항목을 추가하려고 하는데 어떤 이유로 다음 오류가 발생합니다.

[root@centos openldap-servers-2.3.43]# slapadd -n 2 -1 /root/root.ldif 
slapadd: invalid option -- 1
usage: slapadd [-v] [-d debuglevel] [-f configfile] [-F configdir] [-c]
        [-g] [-n databasenumber | -b suffix]
        [-l ldiffile] [-q] [-u] [-s] [-w]

루트 ldif 파일을 넣었고 /root/아래 코드는 다음과 같습니다.

#root
dn: dc=server1,dc=com
dc: server1
objectClass: dcObject
obectClass: organizationalUnit
ou: server1.com

#staff
dn: ou=staff,dc=server1,dc=com
ou: staff
objectClass: organizationalUnit
~     

다음은 slapd.conf의 일부이다.

#
# See slapd.conf(5) for details on configuration options.
# This file should NOT be world readable.
#
include         /etc/openldap/schema/core.schema
include         /etc/openldap/schema/cosine.schema
include         /etc/openldap/schema/inetorgperson.schema
include         /etc/openldap/schema/nis.schema

# Allow LDAPv2 client connections.  This is NOT the default.
allow bind_v2

# Do not enable referrals until AFTER you have a working directory
# service AND an understanding of referrals.
#referral       ldap://root.openldap.org

pidfile         /var/run/openldap/slapd.pid
argsfile        /var/run/openldap/slapd.args

# Load dynamic backend modules:
# modulepath    /usr/lib/openldap

# Modules available in openldap-servers-overlays RPM package
# Module syncprov.la is now statically linked with slapd and there
# is no need to load it here
# moduleload accesslog.la
# moduleload auditlog.la

여기에 누락된 조언이 있나요?