Download the authoritative guide: Enterprise Data Storage 2018: Optimizing Your Storage Infrastructure
Your enterprise cannot afford to lose its most precious resource: stored data hardware. The fact is, that power problems are the largest cause of data loss (about 56.4%) on storage area networks (SANs) hardware: Other problems consist of:
- Power outages interrupt operations at 83% of US enterprises.
- 44.8% of U.S. enterprises have had business operations interrupted because of lightning storms.
- 42% of computer hardware outages are the result of power failures.
Like any other piece of network equipment, SAN hardware needs to be protected by an Uninterruptible Power Supply (UPS) system. With the preceding in mind, Part I of this two part article first discusses why you need a UPS; the different types of UPS that are available; how a UPS is rated; and, how you can evaluate what size of UPS system is needed (or how to calculate volt-ampere (VA) to get the required Kilovolt-Ampere (kVA) size). Part II, continues the UPS for SAN hardware theme by discussing a categorized and prioritized collection of SAN hardware powering needs and problems; avoiding costs from over-sizing a UPS system; UPS lifecycle cost imperatives; UPS rack powering options; power-monitoring software; UPS adaptability/scalability, availability, manageability, and serviceability imperatives; and, next generation UPS systems for SAN hardware.
Before starting the discussion of why you need a UPS, you need to know what it is and how it works. Lets take a look.
What Is A UPSPower interruptions can cause severe repercussions for business computer systems. The problem is especially difficult in places where power outages and fluctuations frequently occur.
Electricity suppliers distribute what is known as alternating current (AC), at a voltage of 230 volts and a frequency of 50 Hertz. The only way of storing electricity, in a battery for example, is to convert the alternating current from the mains power supply into what is known as direct current (DC). Simply speaking, a UPS is a buffer-battery located between the power socket and the computer. It converts the AC mains power supply into direct current in order to charge the battery and then reconverts it back (to AC) in order to supply the load, in this case a computer and/or SAN hardware.
In other words, a UPS provides a backup battery and power inverter circuitry to insulate systems and data from power outages. In situations where momentary power fluctuations occur, a UPS provides constant power to keep your systems running. During extended power failures, a UPS provides backup power to keep your SAN hardware running long enough so that you can gracefully power down. The transfer time to backup is typically very short (usually rated in milliseconds) to maintain system and data integrity. Many UPSs provide filtration circuitry to eliminate voltage spikes, and some also deliver a constant voltage to your systems when the utility voltage surges or sags.
So what types of UPS are available? How do you choose the right UPS for your SAN hardware?
Types Of UPSThe technology employed in the modern UPS has evolved dramatically in the past few years and there is now a wide choice of UPS to suit every type of environment and SAN hardware system. It is no longer simply a choice between online and offline topologies. Line interactive devices have been developed which offer a hybrid solution.
There are a number of key areas which the IT manager needs to consider to decide which type of UPS will give he or she the optimal level of protection. These include:
- Load Size/Battery Time.
- UPS Topology.