Karl Katzke

One method of backup or recovery isn’t enough. Period. No matter what anyone tells you, what the book says, what your boss says, or what you think you need, you need to be backing things up in many ways.

Here’s a few examples.

MySQL

Theoretically, you could recover anything you needed …

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With Dell kit of 1950/860 and newer, I’m using the built in IPMI-over-LAN in the BIOS for stonith instead of messing with DRAC5 or more complicated means. It’s easy to configure on it’s own IP and it just plain works.

First, a security note with people who have their machines …

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You can use pacemaker with ocfs 1.4, but when you’re running service o2cb configure, you need to specify the “cluster stack” pcmk instead of the default o2cb. I haven’t tested this myself yet, but if I don’t blog it, I know I’ll forget it.

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Let’s say you want to keep your logwatch configuration, which has a lot of files deep in directory trees, in subversion to track changes you make over time and ease rollouts between machines.

When you want to check in /etc/logwatch/conf/logwatch.conf. Your working directory is /etc, but /logwatch and /logwatch.conf are …

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This has worked on OpenSuse 10.3, Fedora 9, and all recent versions of Ubuntu…

Problem: Audio doesn’t work when the machine is docked in a Dell dock.
Solution: You need to enable the IEC958 Switch in your Volume Control application.

HowTo:

1. Click Computer, More Applications, and Voume Control
2. Click Edit, Preferences, and check

…

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The version of the command-line svn client for OSX is badly out of date — I think it’s 1.1 or something stupid like that. (Apple has done a poor job of keeping command line utils up to date!)

The SCPlugin available via the Tigris.org website is -OK-, but not …

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I forgot to mention something in yesterday’s post about configuring Postfix with Dovecot and turning on smtp authentication.

When you’re configuring Squirrelmail, you need to make sure that it does smtp authentication. It doesn’t seem that the version that comes with any way to that that *I* could easily find. …

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What a mouthful. Like most other americans who live on a budget, I’m taking a “staycation” this weekend. What better thing to do than to get my mail server migrated to my new VPS? Well, first, I suppose, I should get the mail server all working on the new VPS…

In CentOS, the default Postfix package doesn’t have MySQL support built in. If you’ve got the priorities plugin installed, you’re either going to need to disable it or otherwise work around it so that you get the one from the centosplus repo. Other than that, it’s been made about as easy as it can be… just keep in mind as you’re reading this tutorial that I really loathe administering mail servers and consider it to be a quite onerous chore that’s been made even more onerous by spammers and hackers and script kiddies and what have you.

You’ll need to install: yum install gcc postfix clamav mysql-server mysql-devel spamassassin
dovecot php php-mbstring php-mysql rpm-build. There’s no RPM for Postfixadmin, but it’s available from the project’s site on Sourceforge.

And now the fun begins. This howto assumes that you have a decent level of knowledge and skill setting up services that run on Linux.

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And now the fun begins! Today we’re going to really show some of the power of Zend Framework. All the steps that you’ve taken in the previous tutorials will suddenly make sense — you’re going to be set up to authenticate users in a few minutes flat.

If you don’t know basic OOP (Object-Oriented Programming) principles, now would be a good time to go do some reading on them. We’re going to make heavy use of inheritance, as well as overriding. Just keep in mind that PHP is not a strongly typed language.

Let’s get started. For authentication, we’re going to build the form the old fashioned way so that you can get a good example for ‘how it was done’ versus ‘how smoothly it can be done’ with Zend Framework.

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Today, let’s take a look at Zend_Db. Zend_Db implements a Table Data Gateway, in which the object is considered to be extended to have the properties of a table, as opposed to a Object Relational Model (ORM) / Data Access Object (DAO) where the object is considered to be a representation of the database object. Philosophy aside, it’s a great tool, and we’re mostly interested in how to use it. It is worth noting that you can use Zend Framework along with the excellent Doctrine ORM… and the syntax is even pretty similar.

The general procedure when setting up Zend_Db is to create a bunch of objects that extend Zend_Db_Table_Abstract. When defining an object, you can define what table it connects to, what the primary key is, and any foreign keys that relate to it. Upon instantiating the object in your code, you can use it to build queries against it’s related table, which returns a collection of row sets for direct use in your applications. Today’s tutorial assumes that you’re very comfortable with looping and other control structures in PHP.

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