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JohnyBeGood
Enthusiast
Enthusiast

Good UPS for ESXi 6.5?

Hi,

As the title says any good options?

Found good deal on this model APC Power-Saving Back-UPS Pro 1000 - APC - United States

And was wondering if its a good choice and possibly if it will work shutting down hosts on it?

Thanks in advance!

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daphnissov
Immortal
Immortal

This unit does not appear to be a pure sine wave inverter but instead a modified sine wave product. For servers especially always try and purchase a UPS which outputs a pure sine wave if you can afford it.

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JohnyBeGood
Enthusiast
Enthusiast

Thanks for the reply!

Looks like only higher models have that ie. http://www.apc.com/shop/us/en/products/APC-Smart-UPS-1500VA-LCD-120V/P-SMT1500 ?

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daphnissov
Immortal
Immortal

Yes, pure sine output UPS models are usually the more expensive ones, but they're the only ones that can just about guarantee that when it switches off of utility that your sensitive servers will stay up and running. If this is only a small home lab with no important infrastructure running, maybe don't worry about it; but if this UPS has to support a "production" workload(s), spend the money and put yourself in a good position.

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JohnyBeGood
Enthusiast
Enthusiast

Got it. Yes, its for small home server (Lenovo ThinkServer TS140). Are there any UPS brands/models that are easier to setup for shutdown of hosts in case of power outage? Tried searching but could not com up with anything.

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Kamuthiking
Enthusiast
Enthusiast

hello

APC will do

see the below thread

Shutdown ESXi 6.0 by APC UPS

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JohnyBeGood
Enthusiast
Enthusiast

Thanks for the link! I missed the deal because I did not wanted to buy something that would not work. I'm sure they will have offers in the future.

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recurry
Contributor
Contributor

Sine wave vs simulated sine wave has very little to do with guaranteeing "that your sensitive servers stay up and running". Has almost nothing to do with reliability. The benefit to sine wave is efficiency and RFI. Because of the sharp edges on the wave form a non-sinewave generates harmonics that create some RFI (which won't affect your servers) however, those harmonics don't play well with equipment designed for 60 Hz and in any decent PSU get filtered out and are dissipated as heat. Any sort of device that is an inductive load (has a transformer for instance to step up or down the incoming power) will either operate less efficient (in the case of transformers) or, it some cases not at all. For instance,l the sharp edges wreak havoc with induction motors. Modern computer equipment uses switching PSU exclusively. Unless it's an extremely poor design there will be little noticeable difference in operation and you probably can't measure the difference in efficiency. Remember, a switching PSU first rectifies the power into DC then filters it (the big capacitors) then it chops it up into a square wave anyway so it can be stepped up or down and the rectifies and filters it back to DC.

Fact is though, most inverters and UPS emit a modified square wave (also known as a simulated sine wave) which effectively changes the big sharp leading and trailing edges of the square wave to a bunch of little ones analogous to digitizing a curve with pixels and it's close enough.

The bigger issue actually, is that according to testing and review I came across somewhere (can't remember but I recall it seemed credible at the time) some of the low-end UPS put out quite a bit of spurious noise due to poor switching design and  inadequate filtering whereas most all the mid-range models, even if they are simulated sine wave, have a nice clean output without large voltage spikes.

Odds are you'll never see any difference between a "simulated sine wave" UPS and a "pure sine wave" UPS in the real world as long as you don't buy the cheapest unit you can find regardless of brand (I recall the above mentioned review used APC UPS as examples to make their point).

Cheers,

Ron

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