Admin commands for managing LDAP Server

I did installed IBM Tivoli Directory Server 6.1 as User Repository for my WPS. These are the basic admin commands that i need to execute for managing my server
Starting IDS

1. Go to /opt/IBM/ldap/V6.1/sbin


2. Execute ./idsslapd -I idsinst

Stopping IDS

1. Go to /opt/IBM/ldap/V6.1/sbin


2. Execute ./idsslapd -I idsinst -k

Second approach is starting the Admin Console and starting and stopping LDAP server from there. But when i try to start the server it throws error