Book general available

Since today my book can be puchased in mutiple forms and from multiple bookstores:

• From my publisher Lulu.com the book can be ordered in hardcover paper format (published on-demand) or as an ePUB ebook.
• From Amazon.com the book can be ordered in hardcover paper format (on stock) or as a Kindle ebook.
• From Barnes and Noble the book can be ordered in hardcover paper format (on stock).
• From the Apple iBookstore (for the iPad).

An eBook version will soon be available for the Barnes & Noble Nook as well.

My book is published!!

It is with great pride that I announce the general availability of my first book:

Infrastructure Architecture - Infrastructure building blocks and concepts

It can be ordered from this link from Lulu Press (with a 15% discount for early buyers). There is also an epub version available - check this link 

From the back cover:

For many decades, IT infrastructure has provided the foundation for successful application deployments. Yet, general knowledge of infrastructures is not widespread. Experience shows that software developers, system administrators, and project managers usually have little knowledge of the large influence IT infrastructures have on the performance, availability and security of software applications.

This book explains the concepts, history, and implementation of a robust and balanced IT infrastructure. Although many books can be found on individual infrastructure building blocks, this is the first book to describe all of them: datacenters, servers, networks, storage, virtualization, operating systems, and end user devices.

Whether you need an introduction to infrastructure technologies, a refresher course, or a study guide for a computer science class, you will find that the presented building blocks and concepts provide a solid foundation for understanding the complexity of today’s IT infrastructures.

Fire prevention in the datacenter

Fire is one of the main enemies of a datacenter. Because of the large density of equipment and cables, a short circuit in a cable or a defect in the equipment can easily lead to fire. And because of the air flow in the datacenter and the frequent use of raised floors fires can spread around very quickly.   

Even if a fire starts outside of the datacenter’s computer room, the smoke of such a fire could damage equipment in the datacenter. I know of occasions where the fire was not in the computer room, but in an office. The smoke was not entering the datacenter at all, but the fire fighters demanded to have the power of the entire building (including the datacenter’s UPS) shut down before they could start extinguishing the fire.

Smoke should be taken seriously as well. Even if there is no fire breakout, smoke exposure alone can cause extensive damage to the electronic equipment within the data center. A report by the FCI states that less than 5% of fire damage results from direct thermal damage, while the rest is contributed to non-thermal reasons such as smoke and the inherent gases in it.

Suppressing fire in the datacenter consists of four levels:

• Fire prevention – measures to avoid a fire in the first place
• Passive fire protection – measures to limit the exposure of the fire once it has started
• Fire detection systems – systems to detect smoke and fire
• Fire suppression systems – systems to extinguish the fire once it is detected

Each of the levels above should be taken care of. They are described below.

Fire prevention

The best way to avoid fire damage is to ensure fires do not start at all. Respecting regulations and implementing fire prevention guidelines is of course a good measure. In datacenters the most common source of fires is overheating of equipment or cables. Avoiding “cable spaghetti” is a very useful step in fire prevention, as is not overloading the power supply connections.

Passive fire protection

Passive fire protection limits the exposure of fire once it has started. Measures include the installation of fire resistant walls, floors and ceilings to keep the fire from spreading fast and firewalls around parts of the datacenter to restrict the fire to a certain datacenter compartment.

Be aware of vulnerable entry points, such as cable penetrations, coolant tube penetrations and air ducts. These entry points should be filled with fire resistant material.

Fire detection systems

Fire detection systems allow investigation, interruption of power, and manual fire suppression before the fire grows to a large size. Smoke detectors, flame detectors and heat detectors are usually installed to provide early warning of a developing fire.

Installation of these detectors is a delicate task, as the air flow of the datacenter’s cooling systems must be considered. Early warning signs should enable staff to investigate the alarm and if possible stop the fire using for instance hand fire extinguishers, or simply shutting off the power to overheated equipment.

Fire suppression systems

Fire needs three components: heat, fuel and oxygen. If any of these three lack, a fire will stop. So in general there are three ways to stop a fire:

• Reduction or isolation of fuel
• Reduction of heat
• Reduction or isolation of oxygen

Putting out a fire by reducing heat using water (as used by sprinkler systems or firemen) is not preferred in a datacenter. The damage created by the water might be worse than the fire itself. Therefore in the early days of datacenters fire extinguishing was mostly done using Halon gas, reducing the oxygen the fire needs. Halon extinguishes fire without damaging electronic equipment by replacing the oxygen in normal air with inflammable Halon gas. However Halon is bad for people, as it causes dizziness - not a good combination with a spreading fire.

Today gas based extinction systems are still in use, but they use mostly other types of inert gases, like Argon and special patented gas types (usually combinations of Argon and for instance Nitrogen in a special mix). They have all the benefits of Halon but none of its disadvantages.

Because releasing fire suppression gas in the datacenter increases the pressure in the datacenter with some 50% in a very short time, the pressure peak can break windows, or hurt people. This means that proper vents must be installed when gas based fire extinguishing is used.

PUE

The electricity bill of a datacenter can be very high. Apart from the IT equipment the datacenter itself uses power as well. This power is needed mainly for cooling, but also for lighting, heating of the operator rooms, etc.   

To measure the power used by a datacenter the Power Usage Effectiveness (PUE) is the most used metric. In a white paper published by the Green Grid in February 2007 called "Green Grid Metrics: Describing Data Center Power Efficiency" the use of the PUE metric was introduced.

The Green grid is planning to also publish metrics for carbon usage effectiveness (CUE) and water usage effectiveness (WUE); specially focused on the usage of cooling water.

PUE is determined by dividing the amount of power entering a datacenter by the power used to run the computer equipment in it. PUE is therefore expressed as a ratio, with efficiency improving as it decreases toward 1.

Running a datacenter with a PUE of 2 means that for each watt of power used by the IT equipment an extra watt is used by the datacenter (mainly for cooling). For a datacenter with 1 MW of equipment, another MW is wasted by the datacenter (not leading to better service to customers). In this example, with an average electricity cost of $0.10 per kWh, every year 1000 kW * 24 hours * 365 days * $0.10 = $876,000 is spent on running the datacenter alone (not including the actual IT equipment)! In this example by optimizing the datacenter to a PUE of 1.5 almost half a million dollar per year can be saved.

Over the years the trend has been to decrease the PUE from more than 2 a few years ago to a typical value of 1.8 to 1.5 today. Google claims its datacenters reach a PUE of 1.22, and a Facebook datacenter built in 2011 even claims to reach a PUE of only 1.07, due to excessive optimizations and large scale operations.

It is important to understand that PUE only measures datacenter power efficiency, and not for instance server efficiency, the efficiency of the power supplies used, let alone the amount of useful work that is done by the IT equipment! To optimize the efficiency of the total chain, the useful work done in the datacenter should be divided to the amount of energy entering the datacenter – a metric that is not used in practice today.

Another thing to remember is that a high PUE is not always bad. If a datacenter uses its IT systems very efficiently, for instance by virtualizing all servers to a few large physical systems, much energy is saved. The PUE however will be relatively high as much cooling is needed for the fully loaded physical machines.

Where to build your datacenter

A datacenter can occupy one room of a building, one or more floors, or an entire building. Finding a good location to build a datacenter can be a complex task. There are many variables that determine where a datacenter should be installed. If the datacenter is used for one organization only, it makes sense to place the datacenter inside one of the office buildings. When the datacenter is used by multiple organizations, like in case of an Internet service provider, choosing the location of the datacenter is more delicate.   

Below is a checklist on choosing the location for a datacenter:  

Environment

• Is enough space available to expand the datacenter in the future? The initial datacenter should be designed with as much free space and overcapacity in utilities as possible to allow for growth.
• Is the location vulnerable to flooding (some countries like most parts of The Netherlands are below sea level, are in a vulnerable delta, or are close to a river)? In that case make sure the datacenter is not located at the ground floor or (worse) the basement, but for instance on the third floor.
• Is the datacenter located in a hurricane area?
• What is the chance of an earthquake?
• What is the climate? Datacenter cooling can be easier accomplished and much cheaper in places with a low ambient temperature.
• Is the datacenter close to possible external hazards like a fireworks storage, a waste dump or a chemical plant?
• What is the crime rate? Are there many burglaries in the neighborhood? What about vandalism?
• Is the datacenter near an airport (chance of crashing airplanes)?
• Is the datacenter near an area that is likely to be closed due to unforeseen circumstances (like a car crash on a nearby highway, a forest fire, a military location or a nuclear plant)?
• Is the location close to the home or office of maintenance staff, system managers and external expertise?
• Can the datacenter be reached easily in case of emergencies, maintenance or expansion?
• Are hospitals, police and fire fighters close by?

Visibility

• Is it preferable to have markings on the building showing that this building contains a datacenter?
• Which neighbors does the datacenter have?
• Is the location of the datacenter included in public maps (like http://www.datacentermap.com/)?
• Does the building have windows? Windows are not preferred as they are easy to break into the building and they show to outsiders what is inside the building.

Utilities

• Is it possible to have two independent power providers and internet providers?
• Can cabling routes to the building be determined? Is it possible to have double power and data connections leave the building from two different places?
• Can cabling routes inside the building be determined in a flexible way? Are there multiple paths available to the patch panels, floors and end users?
• Is the datacenter located in a shared building? What if the building must be evacuated? What if the power must be shut down due to maintenance activities of another user of the building?
• Is enough power available to feed the datacenter? How reliable is the power supply?
• Is cheap power available? Can the datacenter use renewable energy like wind power or water power?
• What is the available bandwidth of the external data connections? Is the datacenter close to an Internet exchange point? Are dark fiber connections possible? How reliable are the data connections?

Foreign countries

• Can the country be reached at all times?
• What is the political stability of that country?
• Are there specific laws and regulations you need to adhere to?
• Does the country have a high level of corruption? How reliable is the staff?
• What is the legal status of the data and the datacenter itself?