Monitoring Tomcat with Munin on Debian GNU/Linux

To monitor Tomcat with Munin 2.0 on Debian GNU/Linux (tested on Debian Squeeze with Tomcat6 and Debian Backports), you need the following steps.

First, you need to install package tomcat6-admin which enables the Tomcat Manager app we will be using.

# apt-get install tomcat6-admin

Next, create a user with a manager role in Tomcat, editing /etc/tomcat6/tomcat-users.xml and adding the following two lines in the appropriate list.

Howto reset network device after swapping disks from one PC to another

I had a problem with a very old Compaq PC not detecting the keyboard anymore. I used the PC as a local server, not a real problem, except that the BIOS didn't allow the PC to boot when the keyboard was not plugged in. One solution there might have been to use some USB keyboard (I didn't get a chance to try that - didn't have any USB keyboard lying around). Luckily enough, I happened to have a clone of this computer, so I just swapped the disks from one PC to the other, and booted.

Install Oracle Express and PHP OCI8 on Ubuntu 9.10

Copiado del post de Daniel escrito en el marco de sus proyectos aqui : http://danielphp.wordpress.com/install-oracle-express-and-php-oci8-on-ubuntu-9-10/ (Requirements: PHP 5 and Apache 2 already installed) Go to Oracle website, and download the following files: (You are gonna need to register an account with Oracle to be able to download the files, just do it, its free)
  1. oracle-xe-universal_10.2.0.1-1.0_i386.deb
  2. Oracle instant client basic 11.2.0.1, zip package
  3. Oracle instant client sdk 11.2.0.1, zip package
Instal

Easily avoid using your password in an SSH connexion: ssh-copy-id

On Linux systems, there used to be a mildly complicated but tedious way to allow you to SSH another computer using your public key, which involved finding and copying your public key on the other host, then connecting to the host and putting this key into ~/.ssh/authorized_keys. Now there is a much simpler way to do that... Just launch the following command (with your own data), enter your password, and that's it!
ssh-copy-id  yourusername@remote.host.address
I love administrative simplification!