How to create Instance and Database in DB2

DB2 - in linux platform
1) Create a instance
db2icrt -u instance_name instance_name
* My DB2 location is /DB2/V9.7

Example:
[root@VM01 instance]# /DB2/V9.7/instance/db2icrt -u db2inst1 db2inst1
DBI1070I  Program db2icrt completed successfully.

2) Create Databae
su - instance_owner
export db2instance=instance_name
db2start
db2 create database database_name

Example:
[root@VM01 instance]# su - db2inst1
[db2inst1@VM01 ~]$ export db2instance=db2inst1
[db2inst1@VM01 ~]$ echo $db2instance
db2inst1
[db2inst1@VM01 ~]$ db2start
SQL1063N  DB2START processing was successful.
[db2inst1@VM01 ~]$ db2 create database test_db
DB20000I  The CREATE DATABASE command completed successfully.