Data Center Redundancy: How N, N+1, 2N, 2N+1 and 2(N+1) Match Up

As more and more companies turn to a third-party data center as their IT partner of choice, it is important to evaluate the redundancy measures these data centers have in place to ensure that you are able to conduct business when, where and how you want.

Data center redundancy defined.

Data center redundancy refers to:

  • the way in which the data center infrastructure and the network are designed.
  • the duplicate components which are available and ready to be engaged when needed.

The intent is to safeguard the data center and its clients from any network or facility outages. If a failure occurs, a duplicate piece of equipment maintained on-premise can be installed immediately or an automatic failover to a duplicate system can be initiated.

Redundancy measures can be put in place for the data center’s power and cooling infrastructure, the entire network, hardware and software components, and storage and data management.

Different levels of redundancy can result in different levels of uptime availability across data centers. The challenge for many companies is that they do not understand the subtle differences between them. Here is an overview of each of the levels of data center redundancy.

What does the N stand for?

N refers to the amount of capacity needed to run the data center facility or a specific operation. In an N environment, there is no redundancy so if the power, cooling, hardware or other component becomes inoperable for some reason, you will experience downtime until the issue is resolved.

N+1 Redundancy Explained

If N represents the total capacity needed for full operation, N+1 refers to the total capacity plus a spare or backup component which could be deployed during an outage. It is common in an N+1 environment, that power, cooling and network will have a redundant path. In the event of an electrical outage, a temporary generator or another form of power will be used.

2N Redundancy Explained

If N+1 represents capacity plus a spare, 2N represents two times capacity. The difference is that the spare component referenced in N+1 could be a smaller size or provide less functionality. 2N refers to two identical units. They are equal in size, capacity, and performance.

The benefit of having two identical units is that they are fully redundant. For example, 2N power includes 2 entirely separate electrical systems with each having the same components, equipment, and power sources. Because each system runs independent of the other, they can be more easily and frequently maintained to safeguard against any possible downtime. Should an outage occur on one power grid, the second system can take over immediately, eliminating the possibility that an extended outage would be incurred by the data center’s users.

2N+1 Redundancy Explained

Building on the previous explanation, if 2N describes two completely separate systems, such as two entirely independent electrical systems, then 2N+1 describes two independent systems or devices and one spare.

When describing this level of redundancy, 2N+1 and 2(N+1) are often confused. It is important to understand that they are different.

2(N+1) Redundancy Explained

A 2(N+1) data center provides the highest level of reliability and can virtually assure clients that their applications and data will always be available and accessible.

A data center which delivers 2(N+1) redundancy has double the amount of power needed plus an additional UPS (Uninterruptible Power Supply) system. The probability of failure for a data center with a 2(N+1) level of redundancy is exceedingly slim as multiple component failures can occur without clients incurring any downtime.

MULTACOM Takes Data Center Redundancy to the Next Level

Although infrastructure components like network connectivity, power and cooling are often mentioned when a data center talks about the redundancy measures they have in place, that is just the beginning.

At MULTACOM, we take a more comprehensive approach to redundancy. We incorporate additional measures other providers often disregard completely or are unable to sustain for an extended period of time.

  • Diesel Generators: On-site diesel generators can be refilled on a regular basis. They are able to maintain power indefinitely in the event of a disaster.
  • Contractor Commitments: MULTACOM has standing agreements with various contractors who have committed to arriving on-scene within 2 hours after an outage or disaster has occurred.
  • 24/7 Support: Building engineers are onsite 24/7 so no time is wasted traveling to the facility. They are on top of the situation immediately.
  • Spare Parts On-Site: All spare parts are stored on-site to ensure that they can be accessed and installed as soon as they are needed. We are not waiting around for vendors to drop off new equipment.
  • Power Monitoring: Power is monitored at the rack level, the PDU level and at the main to ensure that every stage is covered.
  • Free IP KVM: Dedicated server clients can easily resolve server issues remotely with a built-in KVM switch. There is no need to spend hours traveling to the data center to fix a problem.
  • Free Hardware Loaners: It may take clients at other data centers hours or days to receive a replacement server or additional piece of hardware from a vendor. MULTACOM clients can request a piece of loaner hardware which they are able to use at no charge until the new equipment arrives.
  • Equipment Inspections: We conduct annual and semi-annual fire detection and suppression inspections, monthly HVAC and dry cooler system inspections, and semi-annual UPS system inspections. These occur more frequently than most other data center providers.

To support the mixed-use, management and storage requirements of our clients, MULTACOM data centers cross the redundancy spectrum including 2(N+1), N+1, and variations of N+1.

The key difference between MULTACOM data centers and others is that we include two important elements which many providers neglect: frequently scheduled maintenance and testing. These are critical elements that, if not regularly executed, can cause component failure and result in lost revenue for every minute of downtime.

Learn more about how MULTACOM’s emphasis on delivering the highest level of redundancy, combined with continual testing and maintenance, can benefit your business. Call us at 800-618-4628.