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Data centre design principles, guidelines and standards

Lee Smith, Director at Dee Smith and Associates

Over the past number of years, practising as a data centre design and management consultant, I've frequently been asked about data centre standards or guidelines and which is the best to apply when designing a new data centre or refurbishing/upgrading an existing site.

In my opinion there are only a few that are "up there". In order to provide insight in this regard I will shed some light on the matter and offer guidance within the context of the African data centre industry.

There is no globally-accredited, official data centre standard. As a result we cannot just pick that one and apply it. There are a number of publications and documents that offer best practices, guidelines and, in some cases, are acknowledged as fully-fledged standards.

In Africa the following publications are arguably the best known:

Publisher                         Title of Publication
Uptime Institute                Data Center Site Infrastructure Tier Standard: Topology
TIA                                   ANSI/TIA-942-A: Telecommunications Infrastructure Standard for Data Centers


Yes, there are others as well but they are not referenced as much in Africa as the ones I mention above. For the purposes of this article I will focus on the two that I believe are most prevalent.


Uptime Institute's Data Centre Site Infrastructure Tier Standard: Topology

In the true sense of the word, this is actually not an official standard. However, it does not at all detract from or reduce the stature of the publication and the high manner in which it is regarded or referenced within the data centre industry. There is no dispute that Uptime Institute, through the vision of the late Ken Brill, pioneered and first published their Tier levels in terms of data centre design redundancy during the mid-1990s.

Uptime Institute uses the word "Tier" as part of their classification nomenclature. The classification range is represented by the roman numerals I, II, III and IV. A "Tier-I" site is the lowest classification and a "Tier-IV" site carries the highest classification.

The design requirements are outcomes-based.

Insight regarding the Uptime Institute certification process:

* Tier certifications may only be conducted by Uptime Institute.
* The process usually begins with a Tier Gap Analysis (TGA). This is a precursor (but sometimes very necessary) to the actual formal certification exercise itself.
* Tier Certification of Design Documentation (TCDD) is the first formal step in the certification process. Once attained, the data centre receives formal recognition of the data centre's design documentation. TCDD is valid for 24 months from date of issue.
* Tier Certification of the Constructed Facility (TCCF) is the final step and ultimate objective in the design and build certification process. TCCF must be completed within 24 months after TCDD has been granted. This is a mandatory requirement for all data centres who obtained their TCDD since 1 January 2014.
* The document itself is periodically revised by the Uptime Institute through their own internal processes as well as validation and endorsement by the Owners Advisory Committee (AOC), a consortium of data centre owners and operators, all of which have received Uptime Institute Tier Certifications.
* Certification covers electrical and mechanical. Some networking is considered, but it's very limited.
The Uptime Institute document is available for download at www.uptimeinstitute.org. You are required to complete a registration page prior to the download.

Telecommunications Infrastructure Standard for Data Centers - TIA-942-A

TIA-942 is approved by the relevant Telecommunications Industry Association (www.tiaonline.org) committees and sub-committees, such as TR-42. It is adopted in accordance with the American National Standards Institute (ANSI) patent policy. The standard covers Telecommunications (T), Electrical (E), Architectural (A) and Mechanical (M) as its major disciplines.

The latest version of the standard was released in August 2012. In March 2014 the word "TIER" was replaced by the word "Rated" as the part of the classification nomenclature. This change was made to differentiate the TIA-942 standard from Uptime Institute. The remainder of the content did not change. The range of redundancy classifications are represented by the numeric values of "1, 2, 3 or 4". Effectively the same principle applies in terms of redundancy where "Rated-1" is the lowest and least resilient and "Rated-4" is the most resilient level for a data centre.

The requirements in TIA-942 are regarded as prescriptive and quantitative.

Insight regarding the TIA-942 certification process

* TIA itself does not conduct audits and certifications. They only publish the TIA-942 standard and provide guidance on process around audit and certification.
* The process of certification begins with a design validation exercise as per the classification rating requested by the client and then independently compared to the standard.
* Once the Design Validation is concluded, a Corrective Action Report (CAR) is issued and subsequently referenced to modify and correct any non-compliance between the current design and the actual rating objective for the specific data centre.
* The data centre owner/investor and supporting team will then use the CAR to ensure that the actual design is aligned with the expectations and requirements specified. This can take any period of time from a few weeks to much longer, depending on what improvements and changes are actually required.
* Once all non-compliance items are addressed and the actual facility has been completed, a final onsite certification audit will be conducted to ensure compliance. This final certification audit is compulsory.
* Upon the success of this final audit, a compliance certificate is issued which is valid for three years.
* A surveillance audit is conducted annually to ensure that no major deviations from the standard has occurred.
* A mandatory recertification audit is required every third year to ensure that compliance to TIA-942 is maintained.
* The TIA-942 standard is formally reviewed by TIA every five years and is available for purchase at: http://global.ihs.com.

For greater detail in terms of the compliance requirements for each of the two afore-mentioned classifications please refer to their respective Web sites and all relevant published documentation.

In general there's not much difference between Uptime Institute Tier Topology and ANSI/TIA-942. I am sure that many may disagree with my comment, including both organisations. Let me give you my take on the obvious differences:

* Uptime Institute Tier Topology is outcomes-based; TIA-942 is prescriptive.
* TIA-942 covers telecommunications and architectural requirements in greater detail. Uptime Institute does not address architectural requirements and it covers only a very small attribute of the entire networking component.
* Due to its prescriptive nature and the two additional disciplines covered, TIA-942 has more page content. Uptime Institute's Tier Topology document has less content but there are additional published papers which further clarify the design components and concepts.
* TIA-942 introduces compartmentalisation at Rated-3. Uptime Institute requires this at Tier-IV.
* In the event of a failure, Uptime Institute requires continuous cooling at Tier-IV. TIA-942 is satisfied if the data centre thermal management remains within the ASHRAE limits for its Rated-4 design. In essence I regard both requirements as being one and the same.
* Only Uptime Institute may conduct formal certifications according to their own classification system. TIA itself does not conduct audits and certifications. However, there are others that do provide audits and certifications based on TIA-942 for commercial benefit. One such company is EPI (www.epi-ap.com), whom I regard as the most experienced and reputable when it comes to TIA-942.

 

The commonalities between the two:

* Both publications and organisations are vendor and product neutral/agnostic.
* Both organisations have long-standing and good track records within the data centre industry.
* Using the criteria of either, data centres can be designed and built against measurable resilience and redundancy criteria. Although Uptime Institute is an outcomes-based framework, the design resilience can still be measured.
* For both it is the certification of the data centre facility itself is the final objective. Design certification or design validation alone does not stand on its own anymore.
* Both classification systems contribute positively and have a beneficial impact on the data centre industry.

In my view there is obvious benefit for the African data centre industry in terms of these classifications. Understand that I by no means detract from any benefit derived from other classification guidelines and standards.


Understanding the data centre audit and certification

A decision to follow the formal route of obtaining a truly independent data centre certification (or to occupy space in a commercial data centre) requires the following considerations:

1. Self-certification or self-auditing is most definitely not advised.

Laying claim to a specific redundancy level without confirmation by an independent and reputable audit and certification authority is of little (if any) value. If a data centre does lay claim to this then potential customers, investors and other stakeholders have every right to request independent and formal proof.

2. Appreciate why you select a specific data centre standard or guideline.

When it comes to data centres, there are many who want assurance that they get what they pay for. In some cases the market demands an independent and formal certification. It may be specified in the requirements of an RFI or RFP where proof is requested to provide peace of mind that the selected (or self-built) data centre will provide what stakeholders and clients demand. Some organisations, especially data centre service providers, use their certification in their marketing and advertising to hopefully obtain a competitive advantage over competitors. For some it's purely a case of economics and the least expensive certification option will be selected.

3. The process to obtain certification requires sustained commitment from all involved.

Any level of independent certification requires resources in terms of design specialists, consultants and advisors, builders, constructors, commissioning agents and funding. It's not just about the financial cost payable to those doing the certification. It is also about the time and effort that is required to ensure that the data centre does eventually comply with the requirements of the classification level.

4. The appointed team must have relevant qualifications, capability and experience.

The consultant or team you select must have the relevant experience and understanding of the redundancy requirements of the selected certification. There must be a proven, verified and successful track record in formal data centre design, build and certification exercises. Understanding the processes and steps involved to obtain certification is a critical success factor. There are many who lay claim to this but only a handful have successfully done it from start to finish. These are the people that you want. And remember, once you begin the process of formal certification, it must be completed or you will have nothing to show for it other than the cost.

5. The local AHJ (Authority Having Jurisdiction) always overrules any classification requirements.

It does not matter what the selected classification requirements may state – if the AHJ states something different then you must comply. This may, in most cases, not affect the attainment of the required certification objective unless there is a glaring oversight in terms of resiliency and/or safety. Always ensure that you understand the local rules, regulations and laws.

6. Executive buy-in and continued support is a critical success factor.

There is no denying that data centres are expensive to build and operate. Executive sponsorship and support will ensure that objectives are reached and that the right focus is kept at the highest levels of the organisation. Without this kind of support the entire exercise runs the risk of losing momentum and, in the worst scenario, failure.

One more important observation
A well-designed, commissioned and formally-certified data centre is but one aspect of this equation. The continued maintenance and ongoing operational management of the data centre are equally important to ensure that the data centre remains functional and reliable according to the original design intent. But this is a subject of discussion in a future article.
Organisations and businesses who are looking to build their own or deploy their ICT assets in highly resilient and robust data centres will do well to actually consider the measured performance, operational reliability and availability of a site.

Conclusion
Whether formal certification is done or not or whether you decide to occupy space in such a formally certified data centre or not, most data centre owners and operators will, at the very least, refer to some recognised standard or guideline. For Africa, in most cases, it is either Uptime Institute's Tier Standard: Topology or the ANSI/TIA-942-A Standard as published by TIA.

Understanding the decision drivers and the implications of this reference is vital to the outcome. A data centre must live up to the design resiliency that is claimed. The applied design philosophy must mitigate the risk of failures and the subsequent loss of downtime. The recognised and regarded standards and guidelines all have the same objective – data centre reliability and availability. The team must be able to deliver on this through their experience, commitment and professionalism.

Also keep in mind that there is no point in merely designing a data centre on paper that meets the criteria of the classification system selected, especially when formal certification is not pursued. Robust design, engineering, execution, quality control and a rigorous commissioning program are all required to ensure that a data centre complies with all aspects of the final design.

Irrespective of what you decide to do, find the right person or organisation that has the capability and experience to guide you through all the steps in the decision making process, execution and the subsequent successful attainment of your data centre objectives.

Feel free to contact us at: info@deesmith.co.za

About the author: Lee Smith is a data centre design and management consultant. He has a wide range of experience, ranging from IT Operations and Engineering through to IT Infrastructure Management. He is an Uptime Institute Accredited Tier Designer (ATD) and a Certified TIA-942 Design Consultant (CTDC), accredited through EPI/EXIN. He is also on the international judging panel for the Brill Awards for Efficient IT. Passionate about his area of expertise, he aims to provide a better understanding about the practical design challenges, implications and other related aspects of data centres. He is available for consulting engagements internationally and can be contacted at lee@deesmith.co.za.

Disclaimer: The views, opinions, analyses and observations expressed in this article are those of the author. It does not necessarily reflect the official policy or position of Dee Smith and Associates, its affiliates or clients, or any other of the author's various affiliations, whether referenced individually, collectively, directly or indirectly.

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