Buying a UPS

TechMinerUK

TechMinerUK

TechMinerUK

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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 :)
 
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? :)
 
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?
 
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 :)
 
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? :)
 
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.
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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) :)
 
What about this one (Delta Electronics 2KVA 'N' Series UPS Model GES202N) also can you point me to the refurbished SMART UPS' as I cant find them :)
 
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bigredshark said:
It's worth noting, the average length of a power cut in the UK (OK, actually in the area covered by UK power networks) has been hovering around 40 minutes for most of the decade.
I've been meaning to try and get some data on the 95th percentile outage time from them but it's broadly safe to say that if you have an hours runtime on battery then power will be restored before you exhaust your battery supply in most* power cuts.
I personally like running a separate UPS for router/wireless as that makes it easy to get 5-6 hours uptime for connectivity to phone/laptop (which is what matters most to me).
* Where 'most' means more than 50%....
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To be honest I've been thinking about this as the networking segment of the house will be away from the servers so that way I can buy two UPS so the router doesn't disconnect if the server UPS dies :)
Rroff said:
I have my NAS setup to shutdown after 15 minutes - shows 2 hours and a bit with everything connected - once the NAS goes down I still get about 5-6 hours on the router assuming the phoneline and backhaul are still functioning.
Over the last 10 years or so we've not really had much in the way of power outages - had a couple of instance recently where it went out for ~10 seconds at a time several times in a row but the rest of the town was out for hours - quite interesting to see the router stats on one of my lines as the SNR, etc. cleared up massively while the rest of the town was out.
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I think I'll have to try this although the more I think about it the more I prefer the idea of two UPS' as it means I can buy them in stages to help spread out the cost as well :)
Liquidfox said:
Your host shouldn't be a DC, ideally it shouldn't be doing anything but being a Hyper-V host.
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I know but right now I don't have the funds to buy another server to run the Hyper-V kit on. Is there any reason why this is a bad idea though as I'm new to all this stuff and once Server 2016 comes out I'll be re-designing the network again anyway :)

BlizzardX said:
I agree with the router/WAP. In NZ we've mostly gone VOIP and the cabinets have their own UPS so generally they survive the power outages ok. I have a small unit that powers my Fritz!box but will need replacing when I get fibre as that uses a different device.
I think a UPS is good for anybody running a server that is expected to be on 24/7 as instant power loss isn't so good for components and storage devices, so while mine won't last more than an hour (NZ has very average power delivery services and so often we have outages of +7 hours during the winter months) it does shut everything down safely, which is critical for a 12 bay synology system running RAID6!
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Haha, 12 bays makes my little 4 bay server setup look "piffly" in comparison and you're right about powering down components properly as I don't particularly want to buy a new server/loose all my data every time theres a power cut (Becoming slightly common in our area due to new houses being build) :)
 
Liquidfox said:
One main one is licensing, by making your host a DC you've now lost a virtual licence. Previously you get two VMs with one physical Hyper-V host, by making your host a DC you've now lost the licence to that second VM. Next is the backups though... if your host was to die running just Hyper-V, that's not too much of an issue. Re-install the OS, quick config of Hyper-v and your VMs are back online.
With your host being your only DC you now have to install the OS, configure Hyper-V AND sort out AD. That massively increases restore times.
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So it would be worth while me getting another DC or Hyper-V server in case it goes belly up :)
At least it currently backups up a separate server to create a full system image :)
 
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