数据中心的发展趋势
Per Brasher
描绘某些个别公司热衷于对之夸大其词的趋势实在是太受人欢迎了。我的公司Yttibrium（Per Brasher是该公司的创始人，同时也是PMC的资深技术顾问）耗费了数周的时间，刨根问底，试图为客户描画出一幅清晰的图画 。以下是针对今后几年数据中心发展趋势的若干核心预测。
追求电能使用效率（PUE）最小化的时代一去不复返
由于美国能源署严格规定，任何获得国家科学基金的项目必须维持PUE在1.4甚至更高水平，而ASHRAE （美国采暖、制冷与空调工程师学会）TC9.条令则建议城市PUE值保持在1.2或更高，几乎所有的建筑公司要么是找到了切实方法，要么是把数据“洗绿”了以满足这些需求。如果你还不了解该计算程式的漏洞所在，只需想一想，若是在系统中加上效率显著提升的IT负载会怎么样…哦？！显然，发明这个方程的目的并非意在中止IT负载层面的任何创新？！
转向机架级别的解决方案
越来越多的机架在远址构建，一旦运至数据中心，只需“分分钟”就可以设置好。许多厂商都将其吹嘘成软件定义的数据中心（SDDC），但实际上，远址集成、常规测试、稳定性老化测试等所节省的成本开支非常客观。企业尚未积极地拥抱这一软件定义的理念，主要原因是成本/风险的计算还不太明确。但机架级的解决方案在成本和风险两方面的优势均十分显著。因此，可以预计，待解决方案供应商们醒过劲儿后，对机架级产品的需求将大幅度攀升。
基于POD的设计
我避免称其为“模块化”或“容器化”的设计，原因在于有些解决方案利用了空置的仓库，在中间摆放一个容载系统；另一些则成排构建，在后门或走道旁放上散热片；还有些公司则把整个建筑拿来使用。数据中心系统的建设正趋向于：消除过去巨大的前期一次性的基础设施的建设投资，随着自己业务增长而逐步购买、扩建数据中心设备。从基础设施的角度来看，任何部件均可以预先设计，再在部署时进行按需复制。同样地，降低风险与成本自然有其优势，因此，预计这个领域也会有快速的增长。
低能耗密度的解决方案是王道
随着经济实用成为了惯常的考量标准，而提供的方案的温度却持续提升，散热能力就成了管理中的重要因素。DCiM工具与应用负载的集成尚有欠缺，尚不理想，因此，就有赖于从密度的角度来降低能耗。由于多数时候，访问速度并非至关重要，所以将会看到数据中心的建筑从城市中心区域向郊区转移的趋势，从而缓解了采纳50+U的机架或高密度计算的压力。
气流方面的优化对全球60%可用地点均行之有效
选择干燥温暖的地方还是温暖潮湿之处？这是个棘手的问题。但是除了用水这一块的节能装置的额外开销，还需要巨大的储水罐来日夜降低水温，这些都会增加总体成本，而对风险控制并无补益。根据其设计说明，所有IT设备（除磁带以外）均可适用于两种系统。此外，也有云和COLO供应商在力图获取额外的成本节约（既能降低构建成本，也能减少运营成本）。
SAS将会成为常用的存储网络
连接在SAS“网格”上的SATA终端越来越常见。其技术挑战在于，当为SATA建立隧道传送数据时，不同速率的端点（磁盘）会阻碍其它端点的通讯。因此我们把这些看成微型网络，可支持多种简化/局限的应用场景：例如保护倒换来实现高可靠性，或者简单的共享和提高可靠性的机制。事实证明，将硬盘从服务器机架上取出并置于独立的外壳内确有其益处（降低了EMI，从而延长了其使用寿命），同样也改善了其服务效率（速度更快，无需工具即可进行替换），但是却缺乏任何网络智能。
值得关注的技术趋势
HDD-> SMR
DRAM-> NVDiMM
IA-> SOC
Tape-> BluRay
NVMe/ PCIE Gen4 得到强势推动
Data Center Trends
It was incredibly popular to write abouttrends that one or another company thought reasonable to self aggrandize about.Yttibrium spent literally weeks sifting through all the mud to get a clearpicture for our clients.
Here is our top pick for the coming year(s).
The Race for a Low PUE is Over
With the DOE having mandated anyonegetting NSF funds must have a PUE of 1.4 or better, and ASHRAE TC9.9 havingmade the recommendation that municipalities require a PUE of 1.2 or better(good option to get more revenue if
you ask me..tax the wasters!) Almost everybuilder out there has either created anoffering, or found a way to ‘green wash‘ the numbers to meet the needs. If youare not familiar with the faultiness of the formula, just think what happens tothe overall number
when you put in significantly more efficient IT load.. oops,that is not the intention of the formula, to stop innovation at the IT loadlevel.
Move to Rack Scale Solutions
Racks are more and more being builtoff-site and once rolled into the DC, provisioned in ‘minutes‘. Many vendorstout this as SDDC, but in reality the cost savings of off-site integrators,test and burn in before the equipment
hist the floor is compelling. Enterpriseshave been slow to adopt much of the SD* due mostly to an unclear cost/riskcalculation, but with Rack Scale Solutions having both lower cost and lowerrisk, expect to see the demand rise significantly as solutions providers
wakeup.
POD Based Designs
I avoid calling them ‘Modular‘ or‘Containerized‘ because some solutions use empty warehouse spaces, and plop acontainment system in the middle, and others build a row, put cooling fins onthe rear doors or over the isle,
and even some build the whole building likethis. Point being the trend to sale as you grow Data Center systems haseliminated the huge up-front costs we saw in the past. Now everything from theinfrastructure point of view can be predesigned, and copy-paste
deployment style.Again lowered risk, and lowered cost has it effect, so expect to see rapidadoption in this space as well.
Low Power Density Solutions Dominate
As economizers are becoming the norm,and the supply side temperatures are being raised, the ability to cool becomesa critical element to manage. DCiM tools are not up-to-snuff yet, with a lackof integration with app loads,
so we look to the density question to reducerisk. Since most access speeds are not critically important, look to see thebuildings trend away from the metropolitan districts in favor of a suburbanspace. this releases the pressure to go to 50+ U racks and high
densitycompute, after all, "land is cheap outside Boise ID".
Airside Economizers Work for 60% of Potential Sites World Wide
The choice of warm and dry vs. warm andwet is a real battle, but with the added losses of the waterside economizer,huge storage tanks are needed to cool the water over night, and use it duringthe day. That makes the overall
cost rise, but does little to reduce risk.
SAS will Become the Storage Network
SATA endpoints on a SAS ‘fabric‘ isbecoming more popular. Challenge is when tunneling SATA, endpoints of differingspeeds, can bugger up things for the others. So we see these as micro nets,allowing a very reduced use-case,
like HA fail-over, or other simpleavailability/sharing needs. The trend to take the drives off of the serverchassis and into their own enclosure has proven better for the drives (loweredEMI etc. makes them live longer) and for service (faster and tool-less
swap),but left us wanting for just a little touch of network intelligence.
Technologies to Watch
HDD-> SMR
DRAM-> NVDiMM
IA-> SOC
Tape-> BluRay
NVMe/ PCIE Gen4 getting a needed shot of steroids
Sensors in the DC, BigData will start to run the DC