Ubuntu 12.04 + virtualbox

So a linux VM running in virtualbox crashed. Well, they all crashed.

But when I restarted the server I was hit with a couple of error. The core one was this:

Kernel driver not installed (rc=-1908)
The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or there is a permission problem with /dev/vboxdrv. Please reinstall the kernel module by executing

'/etc/init.d/vboxdrv setup'

as root. If it is available in your distribution, you should install the DKMS package first. This package keeps track of Linux kernel changes and recompiles the vboxdrv kernel module if necessary.

Scary. But, google is my friend. I found this post in an Ubuntu forum:

http://askubuntu.com/questions/205154/virtualbox-etc-init-d-vboxdrv-setup-issue

It was an excellent review of the problem. The steps that worked for me were:

sudo apt-get install linux-headers-`uname -r`

My headers were up to date so this was not that important, but should be performed regardless.

Then reconfigure dkms and load module:

sudo dpkg-reconfigure virtualbox-dkms  
sudo modprobe vboxdrv

This  got me farther but then received another network error which was solved with:

sudo modprobe vboxnetflt

And now we seem to be back in business.

Review Time

Its that  time of the year where I work. Review time. I'll call it review, but they have some fancy management frou-frou name that conveniently has a three letter acronym. Its sort of a three word version of "screw you".

Can you think of management-speak that means screw-you but can be used for various career and performance reviews? Perhaps this could be a drinking game? Now that I mention it, this is probably how  the term "Personal Business Commitments" was created.

So, I sat there looking at the commitments I made last year, and now one year later they seem so shallow. Pointless. Naive.

And then I had to look at the section on my "development". And this part hurt the most. It hurt because I love learning. I want to learn more. I want to be  the best I can be at my job.

But at the place I work, they not only do not care about my development. They go to great lengths to try to make me "feel" like I am, but at zero cost to them. There are, in reality two costs. Firstly, the cost of the management time they waste on propaganda trying make us "think" we are developing. But then there is the loss of knowledge when people leave (and they are leaving) because they are tired of the propaganda.

As for me? Why was I not being "developed", or developing, or learning? Because they will not pay for any training in my specialisation. And secondly, I have to self-manage everything. From any servers I need to being forced to use their crappy, internal, bottom-dollar tools that don't work. Now that is time I will never see again and never get back.

Its a shame really, because I like the team I am on, and the people I report too.  But the place is a mess.

Python, Factors, and Primes

So my son had math homework on determining the factors of numbers. This was part of a larger mondule on factors, prime, and composite numbers. So after completing the homework together I asked him: "Do you think we can modify our times table program to calculate the factors of a number?".

He thought for a moment and then said: "Yes".

And so we set to it. As it turns out, the program required little change, but the significant new piece of learning was the moduls operator.

We essentially looped from 1 to the given number and took the modulus of the given number by the loop iteration. If the modulus had a value, then the loop iteration was not a factor. If there was no remainder, then it was a factor, which we would print.

Of course this also introduced to him the concept of the if test statement in python.