DB2 Linux configuration

DB2 is now installed and certain  configurations are in order, so that it can be used for something. What should be done is to create certain groups and users for DB2 , create an DB2 instance and configure it to use TCP/IP and certain port.

Create groups and users

sudo groupadd -g 999 db2iadm1
sudo groupadd -g 998 db2fadm1
sudo groupadd -g 997 dasadm1


These groups are handy, if you need to give instance owner group rights to certain users etc. Then create instance owner user, fenced user and admin server user


sudo useradd -u 1004 -g db2iadm1 -m -d /home/db2inst1 -s /bin/bash db2inst1
sudo useradd -u 1003 -g db2fadm1 -m -d /home/db2fenc1 -s /bin/bash db2fenc1
sudo useradd -u 1002 -g dasadm1 -m -d /home/dasusr1 -s /bin/bash dasusr1


Then give each account a password


sudo passwd db2inst1
sudo passwd db2fenc1
sudo passwd dasusr1


Create instance and admin server
Now we are ready to create DB2 administration server instance. In the following the path for commands is /opt/ibm/db2/V9.7/. If you are using other version, then you should change this path accordingly.


sudo /opt/ibm/db2/V9.7.2/instance/dascrt -u dasusr1


Assuming this was successful, database admintration was created and started, and we create db2 instance


sudo /opt/ibm/db2/V9.7.2/instance/db2icrt -a server -u db2fenc1 db2inst1


Now we have to create certain links


sudo /opt/ibm/db2/V9.7.2/cfg/db2ln


Quite probably you will get some errors as a response to this command. Do not worry, it just happened that couple of symbolic links were not created correctly. You can correct them with


cd /usr/lib
sudo rm libdb2e.so.1.0
sudo ln -s libdb2e.so.1 libdb2e.so.1.0
sudo rm libdb2.so.1.0
sudo ln -s libdb2.so.1 libdb2.so.1.0
cd


Networking
DB2 has to able to communicate through network. Edit file /etc/services (as root, of course). Use one of of the following commands to open the file


sudo nano /etc/services
kdesudo kate /etc/services


and add line


db2comm_inst1 50001 # DB2 connection


at the end of the file. You can use other port number if you wish.

Now login as db2inst1 user and start instance.


su db2inst1
. ~/sqllib/db2profile
db2stop
db2start


You should get a message stating that db2 instance was started. It is possible that you get an error. This is because kernel parameter and memory configuration is not set yet. We will worry about that later. Just repeat db2start command, and now DB2 should start.

Now we change into DB2 command line and execute following commands


db2
update database manager configuration using svcename db2comm_inst1
db2stop
db2start
quit


Then execute commands


db2set DB2COMM=tcpip
db2stop
db2start


If everything went well, DB2 is now up and running. You can create a test database with command


db2sampl


If you installed version 9.7 you should now proceed with kernel parameter and memory configuration to ensure that DB2 work efficiently.