Introducing YippieMove '09. Easy email transfers. Now open for all destinations.
Dec
13.

(Warning. This is a quite complex article that requires fairly sophisticated sysadmin/unix-skills. If you don’t have this, this article will probably make you really confused.)

Often when working for small companies, the IT-budget is very limited. Therefore you can probably forget about those awesome gadgets you drawl over in the sysadmin-magazines. Well, I’ve been working like this for years. Running Linux or a similar open source operating system on the servers is a good start in cutting costs, but there’s more you can do.

One of the companies I work for is located on the other side of the world (literally), which makes it hard to access the servers physically. SSH works fine most of the time, but what happens when you have a network error? Maybe the server fails to boot up properly after a power-failure, or maybe you messed up the network-settings and locked yourself out.

If you’re on an unlimited budget this is not a big problem. Then you just order one of these fancy $7,000 IP-KVM switches and this problem is long gone. But what do you do if you don’t have that money to spend on such equipment?

Here’s two different solutions that will work (almost) as good as an IP-KVM, but it takes a bit more work for you as a sysadmin. Remember, all these solution are based on the assumption that you only have Unix/Linux servers in your farm.

Option 1 – If you can afford spending $250-$350 per server.

There is a really nifty product available that is called PC Weasel. This product looks like a graphic card (PCI or ISA), but with a keyboard connector on the outside, and instead of a VGA-connector you’ll find an RS-232 (serial) port. So what this product does it that it emulates a graphic card, but spits out all the graphics to an RS-232.

What this enables you to do is to hook up a null-modem to either a computer or an RS-232-server (such as the ones available here (note that some of the RS-232-servers have SSH-support, making it almost identical to a real IP-KVM-system)). With this all hooked up, you can simply just connect to the serial-port on a different computer and you would see the same as you would see on a regular monitor. You can even access the BIOS – which is the biggest advantage with this solution.

Option 1 or 2 with a RS232-switch.

Option 2 – If you’re really on a tight budget.

This is what I ended up doing. I didn’t feel like paying the $350 or so per server, so I went for the budget solution – plain null-modems.

This solution will take you some more time to get running (if you’re not a hardcore unix/linux expert), but will cost you close to nothing. Once again, this will only work in a unix/linux environment.

The trick here is that we will be using the Linux-kernel’s (or BSD-kernel) serial-console feature to output to a null-modem. It’s not that complicated, but I’m not going to go into details in this post. You simply compile the serial-console module into your kernel, add some settings to your bootloader and your inittab and you’re set.

You can either do this between two servers (and take a chance that they won’t break at the same time), or you can dedicate an old box to be your RS-232-server. You can then just SSH into the box that is receiving the signal and use minicom to control the other box. Note that the big disadvantage with this solution is that you cannot control the servers on BIOS-level. However, it costs you close to nothing, and it will give you more control over the server than with regular SSH.

Option 1 or 2 without a RS-232 switch.

If you have more than two servers, you can build a chain-like system where server one is connected to server two, server two to server three etc., until you close the circle.

For further research I’d recommend the following sources:

Linux Serial Consoles for Servers and Clusters
Remote Serial Console HOWTO

Happy Hacking!

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Introducing YippieMove '09. Easy email transfers. Now open for all destinations.

This article is going to teach you how to get out the big guns against information theft on your Apple OS X machine. ‘But,’ you say, ‘I don’t have secrets and besides no-one cares about my stuff.’ Think again! If you are a normal computer user it doesn’t take long before you have plenty of very interesting information on your laptop, digitized and ready to be stolen in seconds.

A picture of Abraham Lincoln.My secret politically sensitive picture – out in the open and ready to be stolen.
  • Your website passwords
  • Those handy digital bank statements
  • Your accounting information
  • That picture from the office when you were really drunk
  • Your other girlfriend’s or boyfriend’s phone number

Then think about how quickly someone can make a complete copy of all that data: it can take seconds or minutes. And what’s worse, once the cat is out of the bag, it’s likely you won’t manage to get it back in because it will be plastered over half of internet and stored in a database before you know it. We live in the beginning of the information age and information theft is real, fast, and internet enabled.

If you use Safari, most of your passwords are already protected within your Apple Keychain. This guide is about how to protect the rest of your stuff using encrypted disk images. An encrypted disk image is basically a protected folder which you can store on your computer. If you haven’t heard of it yet, encryption is a method to warp data so it can’t be recognized without doing the same process again backwards. In OS X 10.4, this encryption is not toy encryption either. The standard used, AES-128, is the encryption used for ‘SECRET’ level classified information of the American government.

It is all rather simple; just keep in mind that these tips have been written for OS X Tiger (version 10.4) and that things might be a bit different if you have a different version of OS X.

  1. Spotlighting for Disk Utility.Open up Disk Utility. Normally I’d just spotlight ‘Disk Utility’ – like in the picture on the right – but if you need to find it the old fashioned way, look in Applications/Utilities.
  2. Click the ‘New Image’ button in the upper left part of the main window, or go to File>New>Blank Disk Image in the menus.
  3. Type in a nice name for your new disk image. I’m going to call mine ‘My Eyes Only’. I’m also going to make it 40MB big by selecting that from the size drop down.
  4. Set Encryption to ‘AES-128′. Don’t forget to do this or you’re not protecting your data at all!The Disk Utility interface for creating a new disk.
  5. Click create. You will be asked for a password. Make sure you enter something that you won’t forget, because else your data will be gone forever. No-one will be able to get your data out if the password is lost.
  6. My Eyes Only.dmg and My Eyes Only opened on the Desktop.Your image will be created. You can close Disk Utility once it’s done. Now, you will have an image file ‘My Eyes Only.dmg’, which if you double click and enter your password, will open up as an extra ‘drive’ on your desktop. Disk Utility will open it for you automatically the first time.
  7. Once you are done putting files into your encrypted drive, you will need to eject it.

That’s all. Everything you put into your encrypted drive, ‘My Eyes Only’ in this example, will be encrypted with industry standard encryption. Without your password (which you made really sure to memorize and keep safe) it would take thousands of years for a modern day computer to unscramble your data. I’m just going to go ahead and move my Secret.JPG file into My Eyes Only. Here it is in the safety of 128 bit encryption: The Disk Utility interface for creating a new disk.
Once I eject this disk the data will be safe and I can rest assured that my picture is a little bit more safe from prying eyes.

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Introducing YippieMove '09. Easy email transfers. Now open for all destinations.
Dec
03.

A while back Viktor had to make a server redirect from http://domain.com to http://www.domain.com. He experienced some issues because of his lack of control over the server which he wrote about here.

Also the other day we featured an article about the importance of having a unified URL. Since

http://www.domain.com/article.html

looks different than

http://domain.com/article.html

to del.icio.us and similar services, you might not get all that nice attention you deserve. In our article we suggested using Cuzimatter to alleviate the problem. We also linked to a suggestion by Pronet Advertising’s URL’s matter. This article mentions that redirecting everyone to the same URL, if possible, is useful too.

We already use our own solution, Cuzimatter to promote unified links to our articles. But today as you might have noticed, we have also added the other solution: any address on http://playingwithwire.com now redirects to http://www.playingwithwire.com.

Luckily, we have a little bit more control over our own server than Viktor did when he was working with this earlier. So on Playing With Wire, the redirect is as simple as it gets. We use Apache 2 as our web server. Our httpd.conf used to look something like this:

<virtualhost> ServerName playingwithwire.com ServerAlias www.playingwithwire.com

All we had to do was to change this a little bit. (Note that the Redirect pemanent thing should be just one line including the http://… part.) Here’s the modified configuration:

<virtualhost> Servername playingwithwire.com Redirect permanent / http://www.playingwithwire.com/ </virtualhost> <virtualhost> ServerName www.playingwithwire.com ...

All done! Works for every page on the site and does not require slow .htaccess files or complicated mod rewrite rules.

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Introducing YippieMove '09. Easy email transfers. Now open for all destinations.

I was reading on Pronet Advertising that URL’s Matter. Basically the article states that because Pronet Advertising had three different URLs to the same thing listed in del.icio.us they didn’t hit the top of the ‘popular list’. If all the del.icio.us bookmarks had used the same URL, Pronet Advertising would have been much more successful.

The article does a good job describing the problem. More than 3,000 people bookmarked the site but three distinct addresses were used. The article suggests using redirection to make sure that all users see the same page. So for example, if the visitor comes in on http://playingwithwire.com, he or she should be redirected to http://www.playingwithwire.com.

This is sensible but it isn’t enough. Imagine if you have a blog like we do. The article you are reading right now actually appears in three different places, each with a differnt URL! For a while it will be on our front page. It will also be in our archive page for this month. And finally it has its own post page.

Cuzimatter Social LinkmakerUltimately you want everyone to bookmark your posting page because that’s where the article ‘really’ lives. Enter Cuzimatter. By using our clever social bookmarking utility you can ensure that most users bookmark exactly the same page URL, regardless of if they read it from your front page, your archive, your post page, your alternative URL, someone else’s mirror – anything. The Cuzimatter links happily follow your blog post around and make sure bookmark happy users end up bookmarking your page.

If you want a live demonstration just bookmark this page using our Cuzimatter links below. You know you want to. :)

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Introducing YippieMove '09. Easy email transfers. Now open for all destinations.
Nov
21.

A while back I decided to use Mambo as CMS for a company that I was given the responsibility to develop a ‘website with webshop.’ As you might have read in the article Choosing a CMS – Part 1, I recommended Joomla!, but yet I went for Mambo myself. The reason for this is that I wrote the article after I developed the website. In my initial research, I thought Mambo was the better choice, but after using it for a while, I became quite disappointed. For instance, the Mambo-team released a major update release as stable, and two days later withdrew the release, and changed it to unstable. This is quite unacceptable. Sure, they’re just humans, and working for free. But still, it’s really not professional behavior. This caused many sysadmins/webdevelopers (including myself) to spend numerous hours to first upgrade (which was a mess) and then downgrade back to the prior stable release.

I was now in a position where I had a fully working CMS running on Mambo with a webshop full with inventory, and plenty of documents in the CMS. However, I had lost my faith in Mambo, and wanted to switch away from it. Luckily, this turned out to be quite simple.

As the topic reveals, I decided to switch to Joomla!, which is basically just a modified Mambo. The good thing is that many things (such as the config-file) are very similar. Because of this the migration process was quite painless.

At this point I was running Mambo 4.5.4 with the latest service packs. I also had numerous components/modules installed, including VirtueMart. Because of this, my biggest concern was that something would happen with VirtueMart and its inventory.

  1. I guess this goes without even mentioning, but make sure you have at least one set of backups of both the files and the database. I know it’s a hassle making backups if you only have ftp-access, but believe me, it’s worth the effort if something happens.
  2. Download the latest version of Joomla! (which is 1.0.11 when writing this). Download the ‘full’ version and nothing else.
  3. Make sure to inform everyone who needs to know (other admins etc.) that you will be performing an upgrade, so they won’t be accessing the server at the same time.
  4. Log into the admin-interface on Mambo and set the site as offline.
  5. Double check your backups.
  6. (if you only have FTP-access), extract the Joomla! files locally
  7. Upload/overwrite all the files you just extracted to your Mambo-directory on the server
  8. Run the SQL-commands in ‘migrate_Mambo4523_to_Joomla_100.sql’ which you’ll find in the installation/sql directory in you Joomla! directory.
  9. Go to your administration-interface and set the site as online again.
  10. Look through all your components/modules to make sure they’re working properly.

If everything works, be happy. It did for me. If not, you might want to take a look at your configuration.php-file (which was not overwritten by the upgrade). In particular, you want to look at ‘$mosConfig_absolute_path’ to make sure you don’t have any slash at the end, as well as the ‘$mosConfig_lang’ to make sure your language is specified as ‘english’ and not ‘EN’.

Before I upgraded I did quite a bit of research on the Mambo/Joomla forums to see what people said about the migration. Some migration guides were really complex, while other people just overwrote the files and ran the sql-commands (as described above). The guide I wrote above might not be a perfect solution, but rather a ‘quick and dirty’-solution to migrate.

The downside with this guide is that you might end up with files that are no longer used by Joomla!, and then will just take up space on your server, and make your folders look very unorganized. There might also be components/modules that will malfunction after such update. In my migration however, I had no problems with any of my components/modules after the upgrade.

If you followed this guide, please post a comment about your experience (both good and bad).

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