QNotifier seems to be a cool application that can report changes that may impact the performance of your Linux server right to your iPhone. If for example, the apache daemon goes down, QNotifier can be configured to notify you of this.

Installing QNotifier is a little tricky as the installation instructions are very brief.

the following commands will get QNotifier running on your Debian system. I assume this will most likely also run on Ubuntu.

Install Ruby.

apt-get update
apt-get install ruby ruby1.8-dev libzlib-ruby rdoc irb libopenssl-ruby rubygens

Install the update to Rubygens.

gem install rubygems-update
cd /var/lib/gems/1.8/bin
./update_rubygems

Update ruby dependencies for Qnotifier.

gem install hoe rexical racc rubyforge nokogiri archive-tar-minitar sup rails --include-dependencies

Install the QNotifier package.

gem install qnotifier

Run the package to set it up. Get the registration key from the iPhone.

/var/lib/gems/1.8/bin/qnotifier

There are configuration files that can be tweeked to make the package report different information and these config packages are refereced in the short installation guide available from the QNotifier package after you install it to your iPhone.

Following on from my post yesterday about backups, I thought I'd give a further explination as to how to copy down the archives that I created in the script.

For this, I'm using SCP. However, if using SCP, you ordinarily need to log on.

If your prompted for a username and password every time your script runs an scp command, it's kind of pointless having cron run the script at all.

So, to get around the requirement to log in, while at the same time keeping the set up secure, we use an RSA or DSA key.

for the rest of this post, I'm going to call the machines backup and server. The backup is the machine I am copying the backup files to.

On the backup machine, type the following commands to generate the files and copy the public file across to the server. I suggest you use a very restricted account on the backup and server for this.

ssh-keygen -t rsa
hit enter for the first question to agree to save the key to /home/YourUserName/.ssh/id_rsa
Hit enter without typing anything for the second and third questions as we don't want a password for this particular key. Note, this is usually not recommended but it should be ok for this type of situation.
It will tell you that a public and private key has been created and it will give you the finger print of the newly created key as well.

Next, you will want to copy the public key across to your server. Note, the server is the machine that hosts your backup scripts.
scp .ssh/id_rsa.pub YourUserName@ServerName:.ssh/

If this is the first time you've used a public key then use the following command as it will make things easier for you.
scp .ssh/id_rsa.pub YourUserName@ServerName:.ssh/authorized_keys

If however you have used other keys, do the following:
ssh YourUserName@ServerAddress

Type your username and password to log in.

Now, type the following to append the id_rsa.pub to the authorized_keys file.
echo .ssh/id_rsa.pub >> .ssh/authorized_keys

Now, leave the ssh session by typing exit.

From the backup machine, you can now log in via ssh without providing a password.

Note!!!

You might want to secure your public key. If it goes missing, this could go very very baddly for you as this key does not require a password.

Log into the server by typing:
ssh YourUserName:ServerAddress

Now, change the permissions of the file so that this restricted user account is the only one with read and write access to the public key
chmod 600 .ssh/authorized_keys

Now, get out of the ssh session by typing exit.

The next step will be running scp to download your backups and verify that their readable. If their not, we'll want to log the failure.

This is a response to my Blog post about Linux accessibility. I wrote it in response to another comment. It turned into a bit of a long one though and the information is applicable to a lot of things. So, have a read of this:

KDE is based on QT and Gnome is based on GTK. It's important to recognise the differences in these environments from the start. QT doesn't support AT-SPI. It was planned to support this but it never happened. This is down to a decision by the QT developers.
Here's an article that discusses how Gnome communicates with Orca. http://accessibility.kde.org/developer/atk.php

There's information about the accessibility of QT packages at http://doc.trolltech.com/4.5/qt4-accessibility.html

GTK is not the only standard for the graphical desktop manager in Linux. QT is just as much of a player. That's where the problem comes in. Any application that is written for Gnome and follows the Gnome development guidelines will communicate the necessary information to Orca. The problem arises when you launch a QT based application such as Acrobat reader as Orca doesn't get the required information from it.

I understand your point about the limited progress in some areas due to developers not making enough progress with their compliants with the accessibility guidelines but tell me one platform where that isn't an issue. It's nothing to do with communication. It's a problem with bad coding. Simple.

In relation to the problems you have encountered accessing applications that run as root in Ubuntu, there are a number of well documented fixes to this. Basically, Orca, like every other Linux application can not obtain information from a process running as a more privlidged user. This is the reason why Linux is such a secure platform. However, there are work arounds to this as I said earlier. In fact, Listen to one of the recordings in the Linux section of www.lalrecordings.com and you will hear one of the ways of getting around this. In Vinux, the environment is preconfigured for optomal accessibility. Perhaps you should try this out? You might find that with the environment configured to provide the most accessibility, most of your issues are resolved. If nothing else, it will illustrate to you that on most distributions of Linux running Gnome, problems can be ironed out if your willing to spend some time on configuration.

I'd also suggest you read http://live.gnome.org/Orca as I'm almost certain that you'll find an alternative and accessible PDF reader. As for skype, use the plug in for Pidgin. I would bet that you will not find an application that doesn't have a gTK counterpart in LInux. There are very few things in Linux that you will not be able to access if you keep at it. Just like the same can be said in windows or even OSX if your that way inclined.