Slashdot Mirror
UPS Setup For a Small/Mid-Size Company?
An anonymous reader writes "We're a small company employing ~30 people and we are becoming increasingly reliant on virtual servers. Unfortunately, the hosts they are on don't have redundant power supplies because we simply don't have the capacity. We currently have one UPS per rack, which gives us about two minutes. This may have been enough time when they were put in — they've been there for some time — but it isn't really enough time to shut everything down in the event of a failure. Domain Controllers alone may take up to 15 minutes. So I'm looking at upgrading the UPSs to ones that would preferably give us around 15 minutes of breathing space and send an email or text alert when a failure is detected. Something that could trigger shutdowns automatically would also be nice. Of course cost is a key factor too. so given all of the above, what does Slashdot recommend?"
This is sort of off topic, but when was the last time you tested the UPS units that were installed "some time ago". The batteries can eventually go flat. You better check what you have ASAP. You may need to replace them sooner than you think.
I can't remember the brand, but some of the higher end UPS units I have used came with monitoring software. They software polled the UPS unit, and started the shutdown as soon as a power failure caused the switch over to battery.
HTH.
putting the 'B' in LGBTQ+
With redundant connection.
Deleted
It's not about the amount of people, servers, or a fixed time limit to preserve power. First and foremost, you need to identify what the critical systems are that need to be protected. These may include the VM farms, NAS storage, obviously the underlying network infrastructure, and at the very least, some management terminals that can be used in the event of a failure. Once you identify these systems you need to reference the electrical in/output specifications. If possible, you would want to measure the real requirements in production with inline monitors or passive taps. After you have built your requirement set (mind you, you may decide it's better to have a few small UPS vs one very very large one) you need to explore what needs to be up, and for how long, and build yourself a model. There are dozens of UPS manufacturers, and tens of thousands of combinations for any sized company. Once you have an outline of the systems and their individual power requirements, coupled with your own requirements for their availability/protected power, it will be relatively easy to build yourself a good level of protection on a small budget. Mind you these devices (UPS) can often be found on the second hand market due to company refresh, datacenter closures, etc. Many can be easily re-certified by the manufacturer directly or a variety of 3rd party vendors who specialize in this type of infrastructure.
No matter how much battery capacity you have, it will eventually run out. If your site truly needs availability, you have to get a diesel generator.
New UPS batteries and redundant backup generators sounds like the way to go. Even if your UPS only gives you 2 minutes, that should be enough time to fire up a generator.
What's the cost of a good set of UPSes vs simply migrating to a Colo & fatter pipes? Datacenters (most of them anyways) promise at least a few hours of generator uptime, and it sounds like you're already using a colo somewhere (dns relocation, etc).
moox. for a new generation.
Co-locate your equipment at a carrier-grade data center in the nearest major city to your location and get a leased line to your premises. A decent data center will have proper battery backup and generators and know how to handle it. They'll also have the time and manpower to do proper tests, etc.
Learning HOW to think is more important than learning WHAT to think.
You're absolutely right. One place I worked had about 20 employees, 150 servers, but had an income of millions per year. The income averaged out to about $5,700/hr. 12 hours of outages per year could cost almost $70,000 in lost revenue. Is it worth $10k in extra equipment to mitigate that? Obviously.
Smaller companies have to evaluate their acceptable losses. Sometimes it's not worth $100 to make sure you stay up through power outages.
"5 9's" of reliability still leaves 1.14 hours per year of outages. Of course, that doesn't assume that it's all power related outages. Redundancy across physically diverse locations can and will help there.
Serious? Seriousness is well above my pay grade.
The reason your lead-acid battery solution runs so long is that you have A-h (amp-hours) to back it up. If you look in an APC UPS, you will find one or more sealed-lead-acid (SLA) batteries. The ones I've seen are 7 A-h batteries. Say your load is 1000 VA, how long are those 2 little 12V, 7 A-h batteries going to hold up? Do some math, convert the 12V, 7A-h to VA-h: 2 * 12V * 7A-h = 168 VA-h. Divide this number by your load: 168 VA-h / 1000 VA = 0.168 h, or about 10 minutes, optimistically.
Slap a couple of [honking] A-h car batteries behind an inverter, and you easily have lots of run-time. APC and other UPS manufacturers do not seem to want to tell you VA-h capacity of their units, but you can figure it yourself by knowing the capacity of the batteries.
One disadvantage of car batteries is the hydrogen and acidic gases given off by the batteries. They have to be in a separate room from the servers.