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By Chris Angelini |
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IF YOU'VE HIT OUR HOME PAGE IN the last month (www.reselleradvocate.com), you may have noticed that we've been working on a redesign. In particular, that RAM TV graphic, sitting front and center, points to a collection of videos we've created over the past several months. We use a combination of live footage and 3D rendering to demonstrate the value in each of the products or technologies featured, including Intel's DQ965GF motherboard, AMD's CrossFire technology, and the benefits of a mixed SAS/SATA infrastructure. Watch a couple of them when you get a chance. Now, all of that rendering, video footage, and captured audio takes up a sizable amount of drive space, especially with multiple projects under way simultaneously. Since we plan to expand and improve RAM TV coverage, that means we'll need more storage space, more computing power, and greater professional graphics horsepower. We'd already beefed up the internals of our rendering workstation to include NVIDIA's new Quadro FX 4600, based on the G80GL graphics chip. It also has a pair of quad-core Xeons and plenty of memory. The only subsystem not totally decked out was storage. For that, we picked up Belkin's 24U Premium Enclosure, a half-sized rack with lockable mesh doors on both ends, plenty of storage space, and heavy duty casters. Our AIC storage server slid right in, as did the JBOD box, which was connected straight to the server's Adaptec controller. Finally, we were looking at a respectable platform for housing lots of data with enough redundancy to feel relatively safe from an untimely drive failure. But it still lacked protection from downtime should a Seattle thunderstorm knock out the juice from the wall. And so we embarked on our quest to suitably outfit the rack with the best battery backup solution possible. Along the way, we asked the questions needed to ensure the package we bought would cover the load from our storage boxes, deliver ample runtime in the event of a power loss, and accommodate some scalability should we add more hardware to the rack. We also wanted to know about sizing battery backup units, determining infrastructure requirements, and picking the right power protection technology. Anything a reseller kitting out a first rack might want to know, we asked. Pulling Out the Yardstick Our first task was to take the questions a reseller asks in ascertaining a customer's protection needs and sort them out in the best order. "The most essential thing to determine in picking power protection is the load, or the draw of connected equipment," says Joel Gerlach, IT manager at CyberPower Systems. Tripp Lite's Rich Feldhaus, UPS product specialist, adds, "Every customer is set up differently, of course. Getting those customers motivated to figure out their actual draw can be very difficult. They might be convinced that they have their server model number figured out, for example, and they don't understand why we need to know configuration details and information about their power supply. When we're forced to start guessing, customers end up with hardware they didn't really want or need." There are a couple of different ways to tally everything up for your customer, saving them the trouble of trying to size their own UPS and chance the possibility of buying the wrong battery backup. First things first: Put together a complete equipment list. Every item in a rack pulls its own "x" number of watts. And according to Tripp Lite's Feldhaus, solving for that x is the most challenging aspect of picking power protection. List in hand, add up one component at a time. Most components with power supplies very clearly indicate maximum wattage, so it's probably easiest to use watts as your standard measurement. Hardware that doesn't give an explicit watt rating can still be factored in by multiplying input voltage (120V in most cases) by amps. The result is the maximum wattage that device can use. The cumulative wattage of all devices is where you will start your search. One of the first questions that pops up when you're sizing power protection for a handful of servers is whether or not to use one large UPS or several smaller units. A number of variables might come into play as you help answer that one. For example, do the customer's servers have redundant power supplies or just a single unit? In platforms designed to be truly redundant, connecting both PSUs to the same UPS narrows your customer back down to a single point of failure. Should the battery go bad, neither power supply will be able to do its job. Rich Feldhaus of Tripp Lite offers two strategic solutions to that situation: Either deploy separate UPS systems for redundant hardware or connect one collection of cables to a battery and the other to a surge-protected wall socket. Super-Sizing Sockets Multiple battery backups might also facilitate access to more protected receptacles. "After adding up the total draw of each rackmount piece, start counting power cords," says Feldhaus. In addition to total load, the number of devices requiring a socket affects the number of backup systems needed. Should the number of power cords exceed the UPS' capacity, start looking into PDUs (power distribution units). Functionally similar to an everyday power strip, a PDU is much more reliable and much easier to mount. There's really nothing stopping a customer from using a cheap Radio Shack strip to expand six outlets into 12. The problem, according to Tripp Lite, surfaces when it comes time to mount that strip in a rack. Moreover, most power strips have an on/off switch. In a rack environment, that's just one more accidental point of failure as you try to achieve uninterruptible power. The caveat to expanding backup solutions with PDUs is additional cost. Factor in the extra engineering, the contractor-grade receptacles, and the alternative, buying extra UPSes. A little cost up front will save money down the road as components are added to the rack. Sizing up the Infrastructure Another "gotcha" that definitely impacts smaller businesses is power infrastructure. Let's say you need to protect 2,400W worth of gear. The customer is in an office built in 1956, and all of the wall sockets are your standard 15A fare. You decide to use a 3,000VA UPS right at the threshold of where 30A plugs are needed. An electrician comes out to add a 30A breaker and install the corresponding receptacle, only to discover that the building's wiring is of an insufficient gauge. Now you're looking at new wire from the box to the server room. Consider dividing the load between two UPSes and minimizing the infrastructure requirements. Things get sticky when you start talking infrastructure, though. Every locale has its own codes, and buildings all differ when it comes to electrical subsystems. Ask your UPS vendor what will be required to support its latest 3kVA backup system and the vendor, if it's smart, will likely refer you to a local electrician. "We have a hard time generalizing about infrastructure questions," says Tripp Lite's Rich Feldhaus. "So we try to avoid making recommendations one way or another when it comes to getting power to the wall itself." Are you familiar with the building codes in your area? Knowing that UPS vendors aren't comfortable participating in the discussion on how to get the infrastructure side of things handled, a door opens for the reseller to add value by partnering with a knowledgeable electrician able to assess each customer's position and determine "Yes, we can switch the breaker here and add a 20A receptacle no problem" or "No, getting a 30A line to this room is going to require significant rewiring." A Talk About Technology As if it weren't enough that you're already having to optimize for load, for reliability, for the number of power cords coming from the rack, and then for the power coming from your customer's building, there are also three principal types of battery backup from which you have to choose. Fortunately, there's not a massive price difference between them. But the technology you use does influence UPS size, runtime, battery life, and reliability. Entry-level UPSes generally employ standby technology. In a standby design, AC runs through the unit, serving as primary power. In the event of a failure, an internal switch trips and transfers the load to a battery. Where standby units fall short, especially in the professional arena, is that switch from the wall to a battery. It only takes a couple thousandths of a second, but in that gap there's literally no power flowing. That's a disconcerting thought in a business setting. The next step up is more suitable for server protection. Line interactive backup systems still run off of the AC line. However, they employ a transformer that simultaneously charges the battery and feeds the output. A power failure trips the transfer switch, reversing flow from the battery. The result is faster response times and better power filtering. Many line interactive systems support network monitoring and scalable upgrades using extra battery packs. For an SMB populating a single rack, line interactive backup should do the trick. Online, or double-conversion, systems populate the top tier of power protection. In an online configuration, the outputs are driven using battery power, which is constantly refreshed through the AC line. When the power goes out, the battery simply stops getting charged and runs until it's depleted. Should the UPS fail completely, primary power is switched over to the AC line filtered with surge suppression. The benefits of an online UPS include cleaner, more reliable power and the complete elimination of response time worries. On the other hand, there's a lot of engineering that goes into an online UPS. Expect to pay 10% to 15% more for an online unit compared to a line interactive box of the same size. Moreover, because the battery in an online backup system is continuously being charged and discharged, it isn't going to last as long as the cell in a standby or line interactive UPS. CyberPower guarantees the batteries in its Paragon Online families for three years—the same as its Office and Professional lineups, so longevity isn't a problem. But your customer should understand that periodic maintenance is part of deploying battery backup. Calculating Runtime The last step in picking a protection solution is figuring how long it needs to last should the lights go out. "We usually save that question for last," says Tripp Lite's Rich Feldhaus. "Once we know the loading requirements, the necessary connectivity, and infrastructure capabilities, we can present you with a 10-, 20-, 45-, 90-minute runtime solution and so on. It's usually the same answer, in fact, with just more battery packs tacked on." Sometimes customers will read about an outage that lasted three days and decide they need 72 hours worth of power protection. "Though that's certainly possible, when we talk to the business about the cost, weight, the structural engineering they'll need to do to support that many batteries, the request usually drops down to an hour or two of runtime," according to Feldhaus. If a business is under directive to provide hours or days of uptime in the event of a power loss, they're probably using generators to keep things running. The batteries are only used to bridge the gap between power loss and the generators firing up. That might only be one minute of actual mandatory runtime. Right-Sizing Power Addressing the power in a rack might seem like a daunting challenge, but it really doesn't need to be. It's just math. Add up the draw attributed to the hardware you're selling, calculate the number of outlets you'll need, lay an infrastructure foundation according to those power needs, pick the right UPS technology, and come to a conclusion on runtime. In our case, we figured out that the storage servers we're using to house RAM TV wouldn't need any more than a couple of 1,500VA boxes, which use everyday 15A receptacles. We went with online technology and enough battery power to run roughly one hour. Let us know if you can tell a difference next time we post an episode of RAM TV. All of that extra storage should be good for some exciting effects. |
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