How to Choose Data Center Racks / Cabinets

With the rise of colocation, enterprise and edge data centers, the requirements for data center racks have changed from being a cabinet that manages equipment to a rack enclosure that can reduce data center operational costs by preserving valuable floor space, optimizing cooling and increasing the efficiency of IT staff.

There are 6 considerations before choosing a data center rack:-


1) Weight Loads

Today's organizations need data center cabinets that can hold heavier loads and maintain their structural integrity when shipped with equipment. This could mean shipping from their facility directly to a data center, or shipping from an off-site integrator directly to their data center. Shipping a fully-populated rack allows for a faster data center build-out. The raised floor and the maximum floor loading should be considered as well.


2) Open Framed or Closed Frame

Open frame racks typically cost about one third as its equivalent counterpart in a closed frame option. There is nothing to obstruct airflow from circulating through the rack for cooling. But all your equipment is exposed making it susceptible to theft. Your servers' buttons or wires may also accidentally get pulled or pushed.

 

On the other hand, the process of installing or maintaining equipment is trickier for the closed fram racks due to the obstructed nature. If you choose to use this type of rack, sliding rails and shelves for severs and other equipment is highly recommended.

3) Sizing and Capacity

Server racks are sized in units classified as "U" space. Each U represents 1.75". So, a server rack that is 58U is 101.5" tall. The rack height is significant for how much equipment that can be held inside, as well as how much power can be transmitted to equipment in the server storage device. Some organizations may require more space between the server rack and the ceiling for cooling and cabling matters.

Your data center business grows fast. Leaving racks' space for few years later is a good planning for data center expansion.


4) Off-site Integration Processes

Racks should provide the flexibility to accommodate equipment from multiple vendors in a company’s supply chain, and the equipment needs of its data center environment. Many standard cabinets make it difficult to meet these needs, and many companies are turning to custom cabinets to increase overall flexibility and maximize efficiency in their off-site integration process.


5) Multi-vendor IT Environments

Racks need to provide maximum usable space, adequate clearances for airflow, easy access for troubleshooting and reconfiguration of equipment by IT staff and minimize air mixing.


6) The Rising Cost of Cooling

Cooling can be one of the top costs in today’s data center and reducing cooling costs, which can begin at the rack level, can play a major role in reducing overall energy consumption. More powerful equipment and greater data center densities have increased the heat generated in each rack, causing computer room air conditioning (CRAC) units to work harder than ever.

For example, the closed frame racks isolate heat sensitive equipment inside the frame. You have more control over where that air flows with the addition of fans and cooling accessories designed for closed frame racks. Therefore, it is critical to have a rack that supports optimized cooling efficiencies.



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Connecting IT, Facilities and Design


SMA combines with professional Chartered Engineers (CEng) from the Institute of Engineering Technology (IET), the Chartered Institute of Building Services Engineers (CIBSE) and the Hong Kong Institution of Engineers (HKIE). Our engineers have more than 20 years experience in data center design & build, building services engineering and energy conservation in the private and public sectors.

The team exists to provide an interactive environment and opportunities for members of data center and facilities' engineers to exchange professional views and experience, through various training courses, industry events and technical seminars. We prepare the engineers and IT personnel to face any challenges in data centers and critical facilities of any size, in any location.

For other design considerations / topics in data center and critical infrastructure, please visit 


(1) Site Selection,
(2) Space Planning,
(3) Cooling,
(4) Redundancy,
(5) Fire Suppression,
(6) Meet Me Rooms,
(7) UPS Selection,
(8) Raised Floor,
(9) Code & Standards,
(10) Transformers and Harmonic Distortion,
(11) Multi-mode UPS Systems,
(12) Electrical Rooms,
(13) Generator Systems,
(14) Generator Fuel Systems, 
(15) Battery Systems,
(16) Earthing / Grounding and Bonding, etc.

 
   

Data Center Design Consideration: Meet Me Rooms (MMR)

A co-location facility / carrier-neutral data center hosts services from multiple carriers (telecommunication companies) or organizations. Meet-me rooms (MMR) are important physical spaces (2 or more for redundancy) located in the building of a co-location data center or carrier-neutral data center. Data center clients use this space to interconnect or cross-connect to a single or multiple carriers (for redundancy) and to exchange information, which can be transmitted to individual computers via the Internet, without incurring local-loop fees.

Although the concept and practice of using an MMR are not new, the initial creation and management of these spaces over time has become a serious challenge for operators. Owing to some poor practices and lack of building standards, there have been occasions where new clients' preferred carrier could not be accommodated as a result of physical / location challenges. We are going to outline some design best practices.



CABINETS AND SPACE


A carrier generally asks for at least 2 four-post, 84" (45U) high cabinets in each MMR. If the operator is providing only AC power, the carrier may request additional rack space for rectifiers and batteries, should they be using DC equipment.

The best practice is to meet with the intended carriers all at once to create a rack and space solution that they can all agree on. Although this may be a difficult task to schedule, it will be worthwhile to reach an agreement on one typical rack type and one layout look and feel.

Clients who inspect your facilities before signing a contract will appreciate a consistent look to this space. Permitting odd-size cabinets combined with open-frame racks of all colors and widths will detract from a professional look and limit the usefulness of space for new or different functions.

Meet-Me Rooms tend to be smaller because fibers would be run from a user suite to patch panels in an MMR to be interconnected, which requires little space. With time, these rooms have grown in size and are starting to resemble data centers, including features such as cages.



LOCATION


The location of the MMRs would be outside the computer rooms, in the secure data center space. When determining location for one or redundant rooms, consider the industry standards for distance, which will vary according to service type and media (fiber/copper/coax). Placing the MMR on an outside wall is ideal if the space will double as the point of entry so that equipment and workers can go in and out using external doors without disrupting data hall's operations.

Depending on the expected user population, locating the MMR on an exterior wall and even near a loading dock could be a deal breaker for security reasons. If your clients require significantly more security than normal commercial businesses, the MMR should not act a main point of entry but should instead be placed within the data center, away from external walls.



CONNECTIONS


The connection to the data center clients and carriers / MMRs have many methods. Some standards exist. Each method has challenges in co-location facilities, and each challenge can be met so long as they are identified early and planned for.


Direct Connect —

Each carrier connects directly with the client from the carrier-equipment rack to the client-side demarcation point or equipment rack which is also located in a secure half of the MMR (see figure below). The client then extends to the floor space.

The MMR is split for security reasons between clients and carriers. Clients are permitted in their side of the MMR, and carriers in theirs. This approach could increase the amount of conduit in the ceiling space and limit future installations.

Using a private cage for client-side equipment or third-party cross-connect provider as the only staff permitted in the client side of the MMR could limit a security concern.

Direct Connect (Extended Demarcation Point) —

It means each carrier connects directly with the client from the carrier-equipment rack in the MMR to the client-side demarcation point located in the client space (see figure below). Multiple conduits demanded by clients can quickly fill any available space above the ceiling.

Cross Connect in the MMR —

Each client space has pre-installed patch panels located in a secure side of the MMR whereby multiple carriers cross-connect (see figure below). The pre-installed facility is then patched to the client's equipment in the floor space.

Similar to the "Direct Connect" method, some clients may express security concerns with this topology and carriers may not like the potential that a competitor could accidentally unplug their patch. If the MMR is professionally managed (which is highly recommended), the carrier would not have access to this side of the MMR.





Cross Connect in Client's Floor Space —

Patch panels are placed in each carrier’s secure equipment rack and pre-connected to each client's space (see figure below). Drawbacks include higher upfront costs to carriers and operators, who may never connect to every client, and loss of operator cross-connect fees.

MANAGING  MMR


Try to create in-building standards and include them in every lease agreement. In addition, carrier agreements should include adherence to your standards. These standards need to outline access-control, cross-connect, interconnect, and direct-connection means and methods, as well as installation and pathway standards, cable count and color standards, and labeling criteria.

Access Control —

Control access to carrier sides and, if designed, client sides of the MMRs. Only permit third-party MMR management companies to have access to both rooms. Make sure this access is authorized, authenticated and audited. Ensure the design disables any opportunity for a carrier or tenant to literally “throw a cable over the wall” to make a connection.


Connection Methods —

A good cable installer can be assigned to the task of managing the MMR as long as the standards are well documented and SLAs between that company and the operator exist.


Pathway Standards —

The MMR space above the ceiling is not limitless; as such, controls must be put in place to ensure large (and typically unused) conduits are not positioned between data connection points. Traditional cable tray is a sure means of transporting media; most clients will claim that cable trays are an inherent security risk, however. The use of flexible armored cable is something all operators should consider. It is lightweight, able to bend and ultra-thin compared with conduit.


Color Codes —

Color coding the media is a best practice for many reasons. Colors can designate fiber-types, counts, installation dates and specific client connections. Mining out the infrastructure of past clients is easy once the cables are identified, and identification by color is a quick means of disposal.



For details of the MMR and structured cabling system design (copper and fiber cables), please consider to attend a credential program and further learning for telecommunications spaces, horizontal and backbone distribution systems.



About SMA

Strategic Media Asia (SMA) is one of the approved CPD course providers of the Chartered Institution of Building Services Engineers (CIBSE) UK.

The team exists provide an interactive environment and opportunities for members of ICT industry and facilities' engineers to exchange professional views and experience.

SMA connects IT, Facilities and Design. For accreditation details and background, please visit www.stmedia-asia.com/about.html.

Data Center Design Consideration: Space Planning

A data hall houses computers and communications equipment that delivers, store and process information. This is the heart of the data center that operates all mission-critical applications. You need to address 2 key considerations:


(1) Restricting Access

Access to the data hall shall be limited and restricted to only authorized people and to minimize any accidental damage to the computer systems.

(2) Maximizing Floor Space

Floor space in the data hall is extremely valuable due to the high investment placed into the supporting infrastructure. It includes precision air-conditioning, standby power supply, equipment-safe fire protection system as well as security and monitoring systems.



"Non-essential" Items

Sometime "non-essential" doesn't mean useless. To maximize the use and enhancing the security of the area, "non-essential" items should be located outside the data hall. Examples of these items are:


(A) Operating Console / Network Operation Center (NOC)

It houses computer stations connect to the equipment or critical facilities in a data center. NOC may be situated in a separated room / area next to the data hall. Staff can monitor and manage the various systems here and enter the data hall only when they install cables or equipment. It also ensures that the operations and maintenance of the console do not affects the racks/cabinets inside the data hall.

(B) Gas Suppression Systems

Gas Suppression Systems such as FM200 are frequently used in a data center for fire fighting purposes. Gas is used over water as they do not damage the data hall's equipment when discharging. Unlike water, gas should be stored in gas cylinders. Placing these cylinders outside the data hall would allow your technicians to serve them easier.

(C) UPS Batteries & Generators

Uninterruptible Power Supply (UPS), high voltage switchgear and Genset are critical to supply backup power and are usually isolated in different rooms / area:

• Batteries will discharge gas during charging.
• Batteries contain acid that may leak and damage equipment
• Prevention of fire
• For safety reason, only qualified electrical workers are allow to enter the room and serve the high voltage facilities

(D) Air Handling Units (AHU) / Computer Room Air Conditioners (CRACs) Units

It's commmon for a dedicated AHU / CRAC Units to be used in a data room which ensure air from other parts of the data center is not recirculated into the critical area. In addition to being bulky, the AHU or CRAC Units generates heat and maintenance issues. AHU / CRAC Units, therefore, are unsuitable to be placed inside a data hall. Should they be installed in a data hall, they should be placed along the hot aisles.

Maintenance Area

It is important equipment installed in a data center can be repaired or replaced easily without affecting normal operations. Unless we absolutely sure that rear access to the equipment is not required, no equipment should be placed along a wall such as switchgear.

A minimum space greater than the depth of the equipment is required in front or at the back of the equipment which allows

- New parts' installation
- Maintenance or repair
- Airflow (such as hot aisle or cold aisle design)

For racks, a minimum of 1m clearance is observed between racks. A 1.5m radius is usually kept at the end of cabinets / racks which facilitates the use of trolley to move heavy equipment into the aisles.



Raised Floors

Typical raised floor inside a data hall / NOC are 150mm to 300mm (or higher depends on the floor height or design request, you may refer to the international standard / advice in TIA-942 or Uptime Institute). A ramp is usually created at the entrance to bridge the different in heights. It also allows trolley to move heavy equipment. The gradient of a ramp should not be steeper than 1:12.

Per normal practices, power cables (high voltage) are usually put under the raised floor, whereas data cables are usually put inside a cable tray overhead.

Cable Routing

We suggest power cables are separated from data cables. It ensures that the power cables do not pose any electromagnetic interference (EMI) to the data cables. Per previous advice, power cables are laid under the raised floors, whereas data cables are laid overhead.

In addition, data and power cables should be entered a data hall (or other faciliities' rooms) at opposite ends of the area whenever possible to avoid too many cables on one side and EMI problem.

Layout of a data center should be designed to minimize the run of data or power cables. For example, power cables enters the data hall and are routed through

- Riser (Cable Entry)
- Electrical Distribution Box / PDU (Power Distribution Units)
- UPS (High Voltage Switches, etc.)
- Equipment Racks

with minimized distance if they are located near each other relatively.

Expansion

Data Center are used to serve enterprises, government or other organizations. As business or services developed, the demand for faster applications and data storage grow as well. You are advised to allow space for expansion purposes. This expansion space could be located near the entrance of a data center / data hall which allows easier renovation and the installation of new equipment , cabinets and racks.

Cabling, cable trays and empty racks, where feasible, can be pre-installed in the expansion areas. This would minimize the amount of work to be done and the disruption of data center operations / equipment during expansion.



About SMA

Strategic Media Asia (SMA), a critical infrastructure training and event organizer based in Hong Kong, provides an interactive environment and opportunities for members of IDC industry and engineers to exchange professional views and experience on critical infrastructure and E&M facilities.

SMA is one of the CPD Course Providers of the Chartered Institution of Building Services Engineers (CIBSE).

For details of other data center courses and seminars, please visit our website at http://www.stmedia-asia.com/trainings.html.