Shelve the idea of a simple rack

There is much more to the 19″ rack than just a place to park equipment. This humble piece of hardware is often overlooked. But in today’s world, energy efficiency, security, expansion possibilities, strength and flexibility are just some of the factors to consider when choosing a rack. In fact, there is little that is simple about the modern rack. In this article, Rittal looks in depth at the requirements of a modern rack and the duties it is expected to perform in a data centre.

Racks represent the mechanical backbone of all business-relevant IT installations. One criterion which should be top of the list when selecting a rack is stability. Space-saving arrangement of the components in an IT rack, with heights up to 42U, achieves a high packing density and lower operating costs per rack.

The practical consequence is that a server rack must often handle loads of up to 1000 kg, so it is essential for the structure to include a welded frame with multifold profiles, onto which side and door panels can be mounted.

At the same time, the component shelves and slide rails must also be designed for heavy loads. Top-quality racks support up to 150 kg per shelf or rail. Open frames with a 19″ level and high load-bearing capacity can be deployed in air-conditioned IT rooms with access control, where they make installation work easier and allow unobstructed air circulation.

The depth of a rack is also important, as there must be sufficient space behind and in front of the systems for power distribution, cabling and unhindered cooling air flows. Depths of 1000 mm are already standard. Some manufacturers offer their racks additionally with depths up to 1200 mm.

A symmetrical rack design guarantees a flexibly usable installation space and provides suite interconnection in all directions - side by side, around corners and even in stacked configurations.

If such expansion is possible without interrupting operations, this has a positive effect on costs and IT availability.

Interconnected suites and unrestricted expandability, as is the case with the TS 8 racks from Rittal, for example, are furthermore crucial for high-performance rack-based cooling concepts in which the cooling air from air-water heat exchangers is blown in horizontally from the side in front of the 19″ installation level.

The contents of server and network racks are generally valuable and data centres must be protected. Modular security rooms serve as a protective enclosure.

Whether high-security data centre or racks accommodated in an office, the varying demands of the specific business call for individual security concepts with different protection classes.

The choice ranges from basic protection measures to high-availability security rooms with near-zero failure tolerances. To enable adequate reaction to changing corporate needs, economical concepts are modular and can be tailored to the building and availability requirements, for example with a ‘room-within-a-room’ solution.

Freely accessible installation locations, such as offices or collocation rooms, call for corresponding precautions at rack or enclosure level. A robust four-point locking system provides mechanical protection against unauthorised access.

For maximum security, company-wide access solutions integrate a variety of locking and authorisation systems, such as contactless transponders or biometric solutions.

Another alternative is an IT safe, as all-round protection for critical servers. This ‘protective jacket’ is an economically interesting possibility for small and mid-sized businesses. IT safes offer protection against physical threats and can be supplied as modular and basic safes.

In addition to the physical enclosure, diverse configuration options for cooling, power distribution, power backup and monitoring expand the safes into fully featured compact data centres. The Micro Data Centre, developed by the company for SMEs as a joint concept with IT service provider Bechtle, goes one step further still. It is delivered as a complete package and as a plug-and-play system that is available in three configurations with different levels of system redundancy.

Not only access, but also the operating conditions of IT infrastructures must be monitored constantly. One high-performance solution for this task is the company’s CMC III. Sensors provide permanent monitoring of temperature, pressure and humidity. Any deviations are reported immediately.

The management software RiZone builds on the CMC functionality and integrates also the server management level via intelligent interfaces. This permits a holistic view of the data centre status at any time.

The responsible staff are informed automatically as soon as any of the monitored parameters are exceeded. It is even possible to trigger automatic countermeasures. This brings tangible benefits not only in terms of security, but also for efficiency.

There is generally no shortage of cooling demand in a data centre. For low thermal loads up to a maximum of 800 W/m², room climate control can be achieved with a raised floor and air circulation, for example.

For high-performance blade servers, which can easily produce over 20 kW of waste heat per rack, on the other hand, that is not enough. To avoid heat-induced failure of the IT systems in such cases, liquid-cooled rack-based climate control solutions such as liquid cooling packages are used.

These can also be used without a raised floor and can supply a cooling capacity of up to 60 kW per rack. The cold air from an interconnected air-water heat exchanger is blown directly in front of the servers installed in the enclosure via perforated side panels.

Such high cooling outputs, however, are only necessary in exceptional cases and where particularly high computing power is accommodated in individual racks. These rack-based cooling units are also frequently found as energy-efficient ‘suite-based’ solutions in conjunction with aisle containment.

A modular configuration adapted to the arising heat loads and spatial circumstances serves to exclude hot spots and server failures, but at the same time also precludes cost-intensive over-dimensioning of the climate control.

An uninterruptible power supply is an absolute must for every data centre. If preference is given to scalable and energy-efficient rack-based solutions in the initial planning, then the configuration can later grow at favourable cost as demands increase - the PMC product family, for example, supplies up to 240 kW per UPS rack, compliant with the highest reliability standard VFI-SS 111.

The efficiency attained is 95%.

Especially compared to older UPS systems, even a 2% increase in efficiency can add up to a four-figure annual saving in electricity costs.

Careful comparison thus pays off. Every rack needs a suitable power distribution system. From the fused low-voltage distribution, via flexible plug-in socket modules with integrated redundancy to the UPS, it is important that the components are properly matched to each other.

Whether for a large-scale data centre or a single server enclosure, the decision for a 19″ rack system is not simply a question of choosing a particular brand name.

As an integral part of the IT infrastructure, the rack interacts closely with other essential components, such as climate control and monitoring systems, and optimum matching of all individual components is imperative as a basis for trouble-free functioning. This is especially important from the economic perspective, to guarantee flexible scalability and long-term investment value.