In order to migrate Cacti’s rrd-tool data from one system to a different one, that data has to be converted to XML-format first. That is also true if you move from x86 to a x86_64.

To to so, first convert all rrd-data in /var/lib/cacti/rrd to XML using the following line in that folder:

for i in `find -name "*.rrd"`; do rrdtool dump $i > $i.xml; done

Now pack up the resulting XML-files:

tar czf cacti-xml.tar.gz /var/lib/cacti/rrd/*xml

Move the tar.gz-container to the new system and unpack its files in the same directory using:

tar xzf cacti-xml.tar.gz

The re-conversion of those XML-files into rrd format is done using this line:

for i in `find -name "*.xml"`; do rrdtool restore $i `echo $i |sed s/.xml//g`; done 

It happens to me quite often that I forget the root password of a MySQL-setup. In that case, a dirty way to reset the root user’s password is to stop the database and run it with “–skip-grant-tables”. This enables anyone to connect without a password and with all privileges which is certainly not recommended for regular use. After changing the password, the database is supposed to be restarted with regular settings.

The following lines document the actual doing. Remember to replace NEW_PASSWORD in the last line with your new one:

service mysql stop
mysqld --skip-grant-tables &
mysql -u root mysql
UPDATE user SET Password=PASSWORD('NEW_PASSWORD') WHERE User='root'; FLUSH PRIVILEGES; exit;
ps ax|grep mysqld | awk '{print $1}'|xargs kill -9
service mysql start

This article describes the necessary steps to integrate one’s Google-based address book to the Roundcube web-based IMAP client.

For people who tend to keep their personal information like contacts data in one self-managed place, it must seem rather lame to store those data at Google’s. Yet, there are virtually no free open source address books out there that could do what Google offers: full bidirectional sync with basically all mobile devices and support for major protocols. Therefore, using Google as storage for contacts data seems appropriate for the time being. Also, the integration with Google’s Calendar works like a charm. But that’s for another article.

Download of Google Contacts plugin

The necessary plugin can be retrieved from the following website: http://sourceforge.net/projects/roundcubegoogle/files/. It is supposed to be stored in Roundcube’s plugins folder, where it is unpacked by:

tar xzf google_contacts-<version_numnber>.tar.gz

There is a config file alongside with the archive. It’s options do not need customization for general needs.

Creating the database table

In the plugin’s SQL-subfolder there is a file called mysql.initial.sql. After creating a new table called google_contacts in your Roundcube’s database, import the file mysql.initial.sql into the new table.

Installation of Zend package

The Google Contacts plugin needs the Zend GData APIs for it to work. Download the most recent version from http://framework.zend.com/download/webservices and place it into Roundcube’s program/libs folder. After unpacking the according archive, a folder called ZendGdata-<version_number> should be there. In order to have Roundcube finding the relevant libs, create a symbolic link in program/libs as follows:

ln -s ZendGdata-1.11.10/library/Zend .

Configure Google Contacts access

If all went right there should be a new option in a user’s Roundcube settings. Under the section “Address Book” it is now possible to enter one’s Google account name and password. The next access to the user’s address book in Roundcube will trigger the sync with Google’s address book so that all existing contacts will be available.

This posts documents the necessary steps to setup a running Jabber-server in Ubuntu. It uses ejabberd v2.1.5 and by the time of writing it is tested on Ubuntu 11.04.

Installation of packages

First the according Ubuntu packages are supposed to be installed:

aptitude install ejabberd

Customizing the setup

Next step is to customize two settings in /etc/ejabberd/ejabberd.cfg:

%% Admin user
{acl, admin, {user, "youruser", "yourdomain.tld"}}.

%% Hostname
{hosts, ["yourdomain.tld"]}. 

The rest should basically fly by itself.

Now an administrative user has to be added. Is is done on the command line with:

ejabberdctl register youruser yourdomain.tld yourpassword

After this, the server can be started by the following line:

service ejabberd start

If all went well, now the administrative backend should be good to go. It is accessibly with this URL:

http://yourjabberhostname.yourdomain.tld:5280/admin

Customizing the DNS entry

In order to get your server compliant with most of the clients, your domain is supposed to offer the following SRV-entries (example shows bind zonefile entries):

yourjabberhostname       IN A       IP_of_jabberhost
_xmpp-client._tcp        IN SRV     5 0 5222 yourjabberhostname.yourdomain.tld.
_xmpp-server._tcp        IN SRV     5 0 5269 yourjabberhostname.yourdomain.tld.
_jabber._tcp             IN SRV     5 0 5269 yourjabberhostname.yourdomain.tld.

Have fun with your individual jabber server!