Editing DB2 installation

DB2 has been certified by IBM for use inside Virtuozzo. It works in OpenVZ too!

IBM provides a free download of DB2 Express-C which is what I
installed.

Here is a rough guide to installing DB2 into a freshly-created VE.

== Create a new VE ==

I created a new VE for the Debian distribution using debootstrap, as described in [[Debian template creation]].

== Set VE resource limits appropriately ==

These are tested resource limits for x86-64 system running Debian/GNU Linux 5.0.6:

* kmemsize to 26214400:29491200
* privvmpages to 2097152:unlimited
* shmpages to 1572864
* numproc to 400
* tcpsndbuf to 1720320:2703360
* tcprcvbuf to 1720320:2703360
* vmguardpages to 2097152:unlimited
* oomguardpages to 26112:unlimited

And according to DB2 9 documentation, the following minimal guest kernel options must be set in /etc/sysctl.conf:
<pre>kernel.shmmax = 1073741824
kernel.sem = 250 256000  32 1024
kernel.msgmax = 65535
kernel.msgmnb = 65535</pre>

== Install additional packages ==

* libstdc++5 (required for installation)
* pdksh (required for operation?)
* ssh   (may be required for operation)
* xbase-clients (for xauth)
* firefox (for post-installation)
* strace and telnet (for debugging)
* libdbi-perl gcc libc6-dev make (for building CPAN DBD::DB2 package)

== Download the DB2 Express-C package ==

DB2 Express-C version 9 is available from this page:
[[http://www-306.ibm.com/software/data/db2/express/download.html]]

You will need to register with IBM before you can download.

* Untar the received file as root
* Run exp/disk1/db2setup
* Follow the prompts:
** Setup user 'dasusr1'
** Setup user 'db2inst1' and database instance 'db2inst1'

== Post-install actions ==

This is where it gets yukky. DB2 wants to run a browser inside the VPS. It wants to run Java applets inside the browser. I installed Iceweasel, but the post-install script does not recognise it. I was eventually able to hack the script to recognise and use the browser but it crashed on one of the Java applets. I think you can get by without running the post-install.

Here's what to do instead:

First, su to the instance owner:

* su - db2inst1

Try starting and stopping the database:

* db2start
* db2stop

If these don't work it means your environment variables are not set properly. IBM set these for me:

 CLASSPATH=/home/db2inst1/sqllib/java/db2java.zip:/home/db2inst1/sqllib/java/db2jcc.jar:/home/db2inst1/sqllib/java/sqlj.zip:/home/db2inst1/sqllib/function:/home/db2inst1/sqllib/java/db2jcc_license_cu.jar:.
 DB2INSTANCE=db2inst1
 PATH=/usr/local/bin:/usr/bin:/bin:/usr/games:/home/db2inst1/sqllib/bin:/home/db2inst1/sqllib/adm:/home/db2inst1/sqllib/misc

Try creating IBM's sample database:

* db2sampl

== Setup a development environment ==

I develop in perl so I was most interested in access to the database though the DBI library. I did this:

* Use CPAN to download and install DBD::DB2

If you don't use CPAN you can also do this (as root):

* Download http://search.cpan.org/CPAN/authors/id/I/IB/IBMTORDB2/DBD-DB2-1.1.tar.gz
* Untar the file and change into the directory
* perl Makefile.PL PREFIX=/usr
* make
* make test
* make install

== Setup DB2 for autostart ==

It seems that DB2 can be auto-started at VE boot time, but not auto-stopped. I used this script:

 #!/bin/sh
 #
 # Script to start DB2 instances on bootup.
 #
 
 set -e
 
 . /lib/lsb/init-functions
 
 case "$1" in
 start)
         echo Starting DB2
         /opt/ibm/db2/V9.1/instance/db2istrt
         ;;
 stop)
         ;;
 restart|reload)
         ;;
 esac
 
 exit 0

And I used this command to create the symlink to make it start at VE "boot" time:

 update-rc.d db2 start 95 2 .

== Testing your installation ==

From the db2inst1 user, do:

* db2

Inside the db2 client, try:

 connect to sample
 grant dbadm on database to user fred
 connect reset

== Enjoy! ==

Please provide feedback in the discussion (Talk) page about improvements to this HOWTO.

[[Category:HOWTO]]