Roundup of ups Products for Windows
The Uninterruptible Power Supply (UPS) has long been the Rodney Dangerfield of the computing world, but it's finally getting the respect it deserves--and for a variety of reasons. Distributed client/server systems now run many of the mission-critical applications that were once entrusted only to mainframes. These networked systems carry far more risk of power problems than their mainframe cousins--power problems that can cause costly downtime, loss of data, and equipment failure.
According to a five-year study conducted by the National Power Laboratory, the typical North American computer site experiences nearly 300 significant power disturbances each year. A recent study by Contingency Planning Research, Inc. reveals that nearly 50% of all lost data at computer sites is caused not by faulty hardware or software, but by power problems, such as surges, spikes, brownouts, and utility failures.
And the clincher? About two-thirds of the servers in operation today have no UPS protection at all. "Most market studies say that the server market is only 25% to 35% penetrated by UPS products," Doug Milner, Exide Electronics' director of product marketing, said. "It's imperative to protect the mission-critical applications on these servers, and it's equally important to tie the UPSs into a network-wide solution. Yet, you'd be surprised by the number of companies that aren't doing these things. I recently visited a civil engineering firm with 25 servers that weren't UPS-protected. When the weather was bad, they'd send 10 engineers scurrying around the building to shut down the servers."
Some companies do an admirable job of providing backup power in corporate headquarters but fail to adequately protect the communications devices linking them to remote systems. "File servers are of little use to anyone if the communications links that access them experience problems," said Wes Tazzia, marketing director for Controlled Power Company. "The only way to stop a power disturbance from disrupting a network is to put power protection on all current-carrying pathways into the network and to put a UPS between any two pieces of equipment connected via a communications line that is plugged into two different AC sources."
If your system is unprotected, you're taking a very big gamble. "Without the ability to do a graceful shutdown, you can really mess up your [Windows] NT system," according to Vincent Giordano, PowerChute product manager for American Power Conversion (APC).
A terse definition of a "graceful" shutdown in the NT world is: File systems must be correctly shut down, including NT File System (NTFS). Do you have enough backup time to do that--while still maintaining power to every hub, bridge, and router between your server and workstations?
UPS Market Trends
Before I discuss the more technical criteria for selecting UPS hardware and software, let's look at some of the general requirements for most UPSs today: outstanding price/performance, simple installation/configuration, and rack-mount capabilities to save space.
The UPS market is aggressive, and the vendors cited in the directory are locked in some fierce price/performance battles. The UPS power ratings (expressed in VA--volt amperes--or kVA--kilovolt amperes) are climbing while prices are falling. Units can cost anywhere from $100 to many thousands of dollars, depending on their capacity. Once you determine your power needs, you can shop around to get a good price. However, remember that sometimes a higher price tag is justified if the unit boosts productivity because it has superior network power management. The savings can be sizable when a single network administrator does the work of 10 scurrying engineers; then multiply that amount by the number of major outages you experience in a year.
Usually, UPS products are easy to install and configure. Sometimes, however, the hardware doesn't come fully assembled, so you might want to check with the vendor before you purchase a unit. "Our customers want to know that they can take the unit out of the box, plug it in, and walk away," Michael Miga, Superior Electric's marketing manager, said.
Because saving space is a key consideration at many sites, many UPS vendors offer rack-mountable versions that can be installed in a wiring closet. "Some of our customers really appreciate the convenience of having the UPS and all the internetworking gear [together] in one convenient place," commented Marc Vernon, Tripp Lite's marketing communications manager.
Hardware Issues
In the NT world, a UPS product must deliver not just reliable backup power in the event of a blackout, but clean, steady power around the clock to prevent data loss and equipment failure. That's why you should narrow your choice to either on-line or line-interactive UPS products. Most on-line UPSs provide what's called dual-source power to continuously condition and correct the incoming power. They take AC from the wall, convert it to DC, regulate it, and then convert it back to AC power.
If you experience a total blackout, most UPSs deliver from five to 20 minutes of full-load backup time for system shutdown. You need to be aware of how much equipment you are running off the UPS. A 2kVA UPS, for example, should be able to handle about four medium-sized Intel 486 servers, depending on the number of peripherals, display sizes, etc. If you need more time--a longer safety buffer--you can get extended-run backup with add-on battery packs.
Most UPS units come with two-year warranties, and the batteries can sometimes last far longer than that. (For instance, the batteries in many on-line UPSs often last five to six years.) Eventually, however, they wear out and must be replaced. Many units contain hot-swappable, user-replaceable batteries that can be changed without powering down the connected load. In Europe and 14 states in the US, user-replaceable batteries will soon be mandatory to eliminate the environmental hazards of dumping worn-out UPS units without proper battery disposal. The majority of UPS models also do self-diagnostic tests on a regular basis and can be continuously monitored with network software.
Simple Network Management Protocol (SNMP) support is another key consideration. Some vendors offer an SNMP interface card that plugs into the back of the UPS and connects it physically to the network so it can be managed via SNMP.
Scaleability is another important consideration. You should be able to upgrade your UPS's power rating with firmware (say, from 600VA to 800VA by adding a battery unit) instead of having to purchase replacement hardware.
You can also find UPS hardware that supports multiple voltages. "Our Matrix-UPS model does 208V and 120V simultaneously," said Ray DeSabato, APC's Smart-UPS business unit manager. "So if you have a server requiring 120V and an AS/400 needing 208V, you can see some savings."
You should also be concerned with the time required to switch from line power to battery backup. If the switch isn't fast enough, then the UPS does no good because your computer will crash before it can get to the battery. On-line models solve this problem by supplementing line power with battery power constantly, so there is no lag time.