The Open Learning Centre

Hardware

The hardware for the appliance is based on the new and energy efficient 1.6Ghz Intel Atom processor and will be supplied with 1Gb of RAM and a 320Gb Hard Disk in a small sleek case that can hide in a cupboard without the need for monitor, mouse or keyboard. Alternatively for a modest additional charge the appliance can be provided in a standard 19" rackmount case to fit in your datacentre.

Operating System

The operating system of the Libertus is Ubuntu Linux, and includes a graphical user interface to assist in day-to-day management of the server.

How environmentally friendly is it?

Normally the Libertus draws a steady 30W measured at the plug. If we totally max out the processor (calculating the first million digits of Pi in two separate windows to saturate both processor cores) and stress the graphics card by spinning the desktop cube we can get it up to a 40W draw.

Is it a proper server?

Yes and no. It is certainly a very small server by normal standards, and some components would normally be found on a laptop, but it does have some essential server features. One is that it comes back on if the power is interrupted. Another is the hard drive, it isn't a 2.5 inch laptop drive, it is a full 3.5 inch drive which is designed for constant use. It is pretty quick too, spinning at 7200 RPM and we have measured read speeds in excess of 115 MB/sec (that's fast). It is designed to be the ideal low power server for a introduction to both Ubuntu and the application you have specified. The number of users it can support depends on the application you are using and the way you are using it.

If your Libertus is being used for Moodle then it can handle about 50 concurrent users (this means 50 users all requesting or submitting something within a 5 second period), this equates to about 250 real users at any one time as they will be reading, typing and (hopefully) thinking in between requests. We think this should be plenty for a typical school with a student population of about 1000. If you end up using it very heavily, perhaps with lots of video based content, then it might be time to discuss upgrading to a beefier solution.

Detailed info for interested geeks:

Hard drive

This is what the manufacturers call a 320GB drive, we have set it up with a swap partition of the default size (about 3GB) and installed about 3GB of operating system and applications, there is 273GB remaining. We don't think this adds up either, but it is all to do with the difference between units of 1024 vs 1000. The bottom line is that there is quite a lot of free space.

Memory

The Libertus is fitted with one gigabyte of ram (1GB 533Mhz DDR2) in a single slot on the motherboard. It could take a 2GB stick, but you would have to find a new home for the existing memory. If we thought it needed 2GB we would have fitted it.

Processor

The Libertus uses the Intel Atom processor which has very low power consumption it runs at 1.6GHz and is hyperthreaded which means it acts like two separate processors

Slots and suchlike

6USB ports (2 front 4 rear)
PS2 mouse and keyboard
Parallel
Serial
VGA (Intel 945GC graphics, 3D accelerated and really quite nice)
Audio in and out (front and rear)
There is a firewire hole under the front panel but it isn't connected to anything, the motherboard doesn't do firewire.
There is a PCI slot on the motherboard, but there just doesn't seem to be enough room in the case to realistically plug anything in to it.
The Atom processor needs no heatsink or fan, but there is a heatsink and fan on the northbridge and graphics processor.
The case also has a fan.

Operating System

We start by installing Ubuntu 9.04 Server for Intel processors then add packages from the Ubuntu repositories or elsewhere to build the particular appliance ordered. One package we include is the Ubuntu Desktop

Why didn't we use Ubuntu Desktop?

Ubuntu Server and Ubuntu Desktop are basically the same thing, with a different selection of packages. We could have started with Ubuntu Desktop but most of the time the Libertus will not have keyboard mouse or monitor plugged in so we didn't want even the modest overhead of running a graphical user interface. The Libertus will boot up to a simple menu that will allow you to start the desktop.

Why didn't we install the LPIA version?

Programs can be compiled specifically for the Low Power Intel Architecture (the Atom chip) this gives them a few extra optimisations and allows the processor to use even less power. There are issues though, many packages are set up for the i386 architecture and would need to be repackaged for lpia (for example Skype, Opera, Lotus Domino) or you can force the installation on the wrong architecture, which is also somewhat unsatisfactory. All this wouldn't cause much of a problem on the Libertus as it is not intended to be a general purpose machine and running Skype on it is very much unsupported, however when we tried the lpia build the power savings were not very significant.

If you want even more detailed information about any aspect of the hardware or software then please get in touch.