Buying a UPS

Hi everyone, recently I've been looking at rack mounting my servers and networking gear in the house. Since they are going to be in one place I was thinking about providing power backup via a UPS however it's not something I've done before.

My equipment consists of a modem, router, witch, POE injectors and two servers to help gauge my power requirements

Does anyone have any suggestions about what to look for and if there are any that particularly stand out?

Any help is greatly appreciated as always

I've just done this exact thing, installed a used Dell 1920w 11G Rack Line Interactive UPS.

To give you a rough idea, mine is sucking around 500w per hour with the following items plugged in:

1 x Dell R310 (domain controller/TV Server) ~80w
1 x Dell R710 (VMhost 1) ~120w
1 x SuperMicro X8DTi (VMHost 2) ~ 100w
1 x SuperMicro X8DTL (VMHost 3 - Storage with 16 HDD bays) ~100w
1 x HP Procurve 2900-48 48 port 1gbe switch ~60w

I get 24m of runtime if everything was to run continuously until the battery died.

You're biggest power consumers will be the 2 servers and the switch, also how long do you want them to maintain power? Enough time to shut down gracefully and ride out power surges or last long?

Look for an online / double-conversion model made by APC or Eaton. APC have a calculator for working out how much beans it needs to have for your desired runtime.

BlizzardX said:

I've just done this exact thing, installed a used Dell 1920w 11G Rack Line Interactive UPS.
To give you a rough idea, mine is sucking around 500w per hour with the following items plugged in:
1 x Dell R310 (domain controller/TV Server) ~80w
1 x Dell R710 (VMhost 1) ~120w
1 x SuperMicro X8DTi (VMHost 2) ~ 100w
1 x SuperMicro X8DTL (VMHost 3 - Storage with 16 HDD bays) ~100w
1 x HP Procurve 2900-48 48 port 1gbe switch ~60w
I get 24m of runtime if everything was to run continuously until the battery died.
You're biggest power consumers will be the 2 servers and the switch, also how long do you want them to maintain power? Enough time to shut down gracefully and ride out power surges or last long?

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Caged said:

Look for an online / double-conversion model made by APC or Eaton. APC have a calculator for working out how much beans it needs to have for your desired runtime.

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Thank you guys as it should help me plan what I need, just wondering though about buying the UPS and such what is the usual cost and is it okay to buy used?

A used UPS will have a knackered set of batteries and that's the expensive bit to a point. So to answer your question, maybe.

Yup caged is right. I spent a long time ensuring that mine was in ok condition before I purchased, and paid a bit more to get this, even so I'm not certain how long the batteries will last.

If you run virtual machine hosts, then you also want to ensure that the UPS has the management card to shutdown the hosts/vms before power out otherwise all you're really doing is smoothing power fluctuations and allowing yourself time to shut the vms down (and without main power to the rest of the computers it would be a lot harder!).

BlizzardX said:

Yup caged is right. I spent a long time ensuring that mine was in ok condition before I purchased, and paid a bit more to get this, even so I'm not certain how long the batteries will last.

If you run virtual machine hosts, then you also want to ensure that the UPS has the management card to shutdown the hosts/vms before power out otherwise all you're really doing is smoothing power fluctuations and allowing yourself time to shut the vms down (and without main power to the rest of the computers it would be a lot harder!).

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Wouldn't Hyper-V shut down/suspend the VMs for me?

Not if Hyper-v doesn't know the power is about to be cut! I'm not sure what UPS you will get but if you have baremetal device (e.g. standalone domain controller etc) then you can generally connect via USB and use that machine as the controller for the UPS, if not then you'll need lan access to the UPS.

BlizzardX said:

Not if Hyper-v doesn't know the power is about to be cut! I'm not sure what UPS you will get but if you have baremetal device (e.g. standalone domain controller etc) then you can generally connect via USB and use that machine as the controller for the UPS, if not then you'll need lan access to the UPS.

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The machine it will be connected to will be the DC but it also does the Hyper-V and system backups as well

That should work, you just need to get the right software and usb cabling to do this... Sometimes you're lucky and the UPs will have the management card already installed like mine had.

BlizzardX said:

That should work, you just need to get the right software and usb cabling to do this... Sometimes you're lucky and the UPs will have the management card already installed like mine had.

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Does it matter if it's APC or not as their calculator suggested 900VA/540W so if I got a different brand with those it should be the same as the outputs match?

I would suspect not. Its should just be calculating storage requirements based on inputs and time to run out of power... you'll probably find something along the lines of a 1KW unit for quite cheap from eBay etc. if you want to go second hand, or not that expensive new if you look.

I went for the 1920w unit as I wanted my TV server to survive as long as it could so effectively my esxi servers start to shut down after 10 minutes with only the storage server and server 2012 r2 essentials server running until around 2 minutes before power runs out; this gives the tv server (essentials) around an hour or so before it dies after they've shut down, plenty to probably finish recording something and then safely stop.

I have a couple, a APS one (several years old)
and this year I got a new one for another server
Powercool Smart UPS 1000VA

I like it its only been used a couple of times but it did the business when needed

Remember that a UPS will draw its own power as well what it will draw for the batteries or powering its sockets; I've probably added around 50/60 watts extra with my UPS... Always worth considering for financial reasons!

take a look at ups-trader on the auction place for refurbs.

got my apc smart-ups 1500 from them several years ago and has been spot on. got a new set of batteries from them too (had it that long) and their after sales was very good.

neil_g said:

take a look at ups-trader on the auction place for refurbs.

got my apc smart-ups 1500 from them several years ago and has been spot on. got a new set of batteries from them too (had it that long) and their after sales was very good.

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This.


I've always used 1500-2200va UPS's. Smart UPS only. Avoid Back-UPS from APC. The later versions have a different comms protocol which some open source software doesn't support yet (for shutting down machine etc).

IIRC the 2200va unit has a load rating of just over one killowatt.

Don't put any laser printers on a UPS

BlizzardX said:

Remember that a UPS will draw its own power as well what it will draw for the batteries or powering its sockets; I've probably added around 50/60 watts extra with my UPS... Always worth considering for financial reasons!

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True but it's probably cheaper than repairing the server if something dies during an outage

neil_g said:

take a look at ups-trader on the auction place for refurbs.
got my apc smart-ups 1500 from them several years ago and has been spot on. got a new set of batteries from them too (had it that long) and their after sales was very good.

Click to expand...

ov_sjo said:

This.
I've always used 1500-2200va UPS's. Smart UPS only. Avoid Back-UPS from APC. The later versions have a different comms protocol which some open source software doesn't support yet (for shutting down machine etc).
IIRC the 2200va unit has a load rating of just over one killowatt.
Don't put any laser printers on a UPS

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Thanks guys however would I get away with a 1000VA UPS as the others start to get slightly out of my price range (Don't worry, no printers will be on the UPS haha)

they do others, not just the 1500

neil_g said:

they do others, not just the 1500

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I know but I've spotted UPS-17680 Trust Oxxtron one which is 1000VA for cheap

What exactly is your budget? You can get re-furb Smart-UPS 1500's for £100 on eBay.