A discussion on current trends and technical questions confronting the data center industry spanning the disciplines of mission critical facility siting, development, and design; colocation; managed hosting; infrastructure as a service; cloud; and beyond....
Thursday, November 11, 2010
Icelandic Data Centers - from my Iceland 101 Blog
Wednesday, November 3, 2010
Latency and Data Center Siting
- Companies whose system require care and feeding by a staff in a specific geographic location.
- Privacy laws that require the data be kept within certain boundaries.
- Disaster recovery and accessibility concerns.
- Physical latency which is the time that it takes to communicate with the facilities.
Friday, October 22, 2010
Does the Equinix "miss" Signal the Beginning of the End?
- Customers today consider moving a viable option - the move to virtualized environments and converged architecture make it easier for data center users to migrate to a new facility. This is amplified by the fact that many customers are currently implementing these solutions and require some type of migration - either in place or to a new facility.
- There is an efficient marketplace - the emergence of national/international databases, reporting, and competitive placement have made it very easy for customers to understand what market rates are and to obtain competing proposals.
- Capacity is not constrained in most markets - the facility expansions of recent years combined with improvements to many facilities mean that there is available capacity in most markets.
Monday, March 8, 2010
kW vs kVA in the Data Center – It really matters!
Understanding the difference between kVA and kW is critical to proper operation of a data center. The equation is simple – kW equals kVA multiplied by the power factor, but the implications can be a little more complex.
Power factor is the ratio of resistive to reactive power. In layman’s terms resistive power is burned on the spot whereas reactive power does not burn all of the power and “bounces” some back into the system. A lightbulb is an example of resistive power while an electric motor produces reactive power. Most electric systems and utility grade equipment are designed around a power factor of 80%. Most data centers, on the other hand, are almost completely resistive load and have power factors approaching unity (100%).
Since the data center power factor is high and, as such, kW is very close to kVA, some people discount the difference and use the two interchangeably. This is very dangerous and can lead to the creation of “phantom” capacity.
The fundamental limitation crops up in how much capacity critical equipment such as the generator and UPS have. Most of these systems are designed for a power factor of 80%, which means that they can only produce kW equivalent to 80% of kVA.
What does this mean. Let’s walk through a sample calculation. A data center is filled full of 120 V circuits where the customers are allowed to draw up to 16 Amps, which is equivalent to a kVA of 1.92. If we assume that this equipment has a power factor of 95%, this is equal to 1.82 kW. If we look at the other side, the 600 kVA UPS has a power factor of .8, so it produces 480 kW. So the capacity of the UPS is 480/1.82=263 circuits. If we had done “simple” division on the kVA side, we would have had a capacity of 600/1.92=312 circuits. So we actually have 49 fewer circuits than the “simple” math would have indicated, hence the reason that it is critical to convert all loads and capacities to kW!
Recently, manufacturers have begun to address this by designing systems with higher power factor ratings. A few companies are also marketing retrofit kits for existing UPS systems to increase the power factor rating.
Check back in a few weeks for the next installment – “Implications of Data Center Power Factor for the Utility Grid”.
Wednesday, December 2, 2009
The Significance and Challenge of Tier Ratings
Over time it has been supplemented by broad interpretations, no doubt to the at least ocassional dismay of its developers. These interpretations have been somewhat of a necessity given the lack of flexibility written into the standard.
For example, each tier specifies a minimum height for raised floor. This leads some people to the erroneous conclusion that data centers without raised floor are somehow less reliable. This interpretation is incorrect . Raised floor allows for different design and operational implementations but neither those implementations or the raised floor itself impart more reliability. In fact, in high seismic zones just the opposite IS TRUE - slab has a higher calculated reliability than raised floor.
Calculated reliability is where we need to go as an industry. We need to thoroughly analyze design and operating standards to identify single points of failure, sources of cascading failures, maintenance considerations and a range of other concerns that determine reliability. Where appropriate, we need to back these up with detailed and vallidated calculations.
Monday, November 23, 2009
Equinix Purchase of Switch - Decline of the Massive Data Center
So did Switch reinvent itself or Equinix radically alter its strategy? In truth a little of both happened, but even more this is an indicator in a significant shift in market direction influenced by a number of factors.
What seemed like an insatiable drive for higher power density and ever bigger and more reliable data centers has slowed if not all together abated. Although motivated by the drive to reduce energy costs. the shift to virtual environments is also starting to significantly impact data center procurement.
The trend in developing a hardware platform for a virtual or cloud implementation is to seek the optimum price point for hardware, which often means stopping well short of top of the line high density blades. Architecture is also advancing such that many clients are achieving distributed and self healing computing environments. Even though we have seen some celebrated "cloud failures" there is an increasing number of customers seeking lower physical infrastructure reliability, and price points.
I haven't even touched on potential shrinking footprints with full-scale virtualization, but let's just suffice to say that Equinix apparently views it wiser to invest more in broadening their foot print and product line and (perhaps) less in building new mega data centers.
Saturday, November 21, 2009
Colocation in Central Europe
In some facilities it was a trip back to the early 90s. Some of these facilities had literally hundreds of tower servers on utility shelves like you would use for storage in your basement. Apparently, this has remained a low cost hosting option in Central Europe. Most of these facilities are fully lights out. If the customer cannot fix their server remotely, it is removed from the data center for them to work on it. Customers are not allowed on the data center floor.
There is also a considerable amount of hosting by the U, managed services, and cabinet colocation. Most communication is via VPN or dedicated telco circuit, with very little metro ethernet.
Internet connectivity is almost exclusively to the west, with Frankfurt, Vienna, London, and Amsterdam noted as popular interconnection points.