CCleaner utility for Windows

CCleaner is one of my favourite utilities for Windows. It does several things very well.

One of them is removing the temporary files that various applications leave lying around. For example, the Windows temporary files directory gets filled up with various installers that have a tendency to never be removed as well as fragments of files left open during crashes. For another, Windows retains the option to let you uninstall every patch Microsoft issues. This may be useful in a mission-critical server situation, but on a regular machine it just wastes space.

I just had to clean up a very space-constrained virtual machine for work. CCleaner instantly freed up 1.4GB of space simply by removing crud left around by installers and other applications.

CCleaner also does a beautiful job of correcting Registry inconsistencies, finding dead Start Menu shortcuts, and various miscellaneous tasks like free space management and cleaning up the Add/Remove programs list.

• Download CCleaner

Blog dehacked

I apologize if you saw any strange malware warnings last Friday. Someone exploited a hole in my rather old installation of WordPress and added a nasty Javascript scriptlet to every post. They also published every one of my drafts and also truncated every post title to a single word.

Google Webmaster Tools alerted me to the situation with an email. They have since confirmed that all the malware has been removed.

This involved upgrading WordPress to 3.0 as well as going through every post to remove the payload and fix the title. I took the opportunity to purge many of the posts.

WordPress 3.x seems much nicer than my creaky old install of WordPress 2.x. The widgets are very handy, as is the integrated update functionality for both WordPress and WordPress plugins.

Simplify the DB2 9.7 security model

Starting in DB2 9.7, the DB2 security model was changed. Security administration (SECADM) was split off from database administration (DBADM), and users with SECADM permissions could no longer peek at data, at least not by default.

Secure by default is a great practice. It’s fantastic when deploying a production database at a financial institution. However, it’s not so good when you are a new user trying to learn a tool.

Control Center seems to run as SYSTEM by default on WinXP, which leads to errors like this:

SQL0551N  "SYSTEM" does NOT have the required authorization
OR privilege TO perform operation "SELECT" ON object "LEONSP.ACT".
SQLSTATE=42501

Let’s remedy this by granting lots of privileges all around.

Open up the DB2 Command Window.

Connect to the database as a user that already has permissions (leonsp for me):

db2 connect TO samptest user leonsp USING password

Grant all privileges to SYSTEM:

db2 GRANT  DBADM, SECADM, CREATETAB, BINDADD, CONNECT, CREATE_NOT_FENCED_ROUTINE, IMPLICIT_SCHEMA, LOAD, CREATE_EXTERNAL_ROUTINE, QUIESCE_CONNECT ON DATABASE  TO USER system

Did you create DB2ADMIN or some other id when installing DB2 on Windows? Let’s grant all privileges to that user as well:

db2 GRANT  DBADM, SECADM, CREATETAB, BINDADD, CONNECT, CREATE_NOT_FENCED_ROUTINE, IMPLICIT_SCHEMA, LOAD, CREATE_EXTERNAL_ROUTINE, QUIESCE_CONNECT ON DATABASE  TO USER db2admin

You should now no longer see the SELECT privilege error. Note that you should not do this in a production environment, as this is less secure than the default configuration.

Cataloging databases after reinstalling DB2

On Windows, uninstalling DB2 will remove the instance but keep the databases in place. After you reinstall, you’ll want to recatalog these databases. This is fairly straightforward.

Find out their names:

db2 list db directory on C:

Map each of the databases that you want:

db2 catalog db SAMPLE on C:

You can also catalog remote databases the same way. In my experience, this is much easier than going through Control Center:

db2 catalog tcpip node MYNODE remote MYHOSTNAME server 50000
db2 catalog db SAMPLE as MYSAMPLE at node MYNODE
db2 connect to MYSAMPLE user MYUSER using MYPASSWORD

The database will now show up in your Control Center catalog. You will also be able to connect to the local alias from Data Studio and other tools.

Going from DB2 Enterprise to DB2 Express-C

Downgrading from DB2 Enterprise to DB2 Express-C is a fairly straightforward process.

Stop DB2.

db2stop force

Uninstall DB2 Enterprise.

sudo su - db2inst1
/opt/ibm/db2/V9.7/install/db2_deinstall -a
exit

Install DB2 Express-C without creating any users, etc.

sudo ./db2_install

Update the instance with the new edition information.

sudo /opt/ibm/db2/V9.7/instance/db2iupdt db2inst1

You might encounter this error.

db2inst1@vhost0074:~> db2start
SQL5043N  Support for one or more communications protocols
failed to start successfully. However, core database manager
functionality started successfully.

Look up your DB2 TCP/IP service name. It should be similar to db2c_db2inst1 where db2inst1 is the instance owner.

cat /etc/services | grep db2

Make sure it’s set correctly in the DB2 configuration.

db2 update dbm cfg using SVCENAME db2c_db2inst1

Start DB2.

db2start

You should now have a working DB2 Express-C installation with all the same databases.

Enable NFS services for HADR

You might need to enable network file system (NFS) services when configuring the High Availability Disaster Recovery (HADR) or Database Partioning (DPF) DB2 features. For example, with HADR, you might want to set up a slave database that shares a backup with the master database through NFS.

These commands should enable NFS services on most distributions of Linux:

sudo /sbin/chkconfig nfs on
sudo /sbin/chkconfig nfslock on
sudo /sbin/chkconfig rpcgssd on
sudo /sbin/chkconfig rpcidmapd on
sudo /sbin/chkconfig portmap on
sudo /etc/init.d/iptables restart
sudo /etc/init.d/nfslock restart
sudo /etc/init.d/portmap restart
sudo /etc/init.d/nfs restart

Some of the services might not exist on your distribution. Additional steps may be needed.

IBM Smart Business Cloud for Test & Development might be one of the environments where you’d have to do this.