UPS for section of my network

[Jay]

I need to upgrade to a proper UPS for a node. Its never really been that important but these days it sees a lot more traffic than it once did so uptime is key.

At this location I run 1 x Cisco WS-C2950-24 switch, 2 x Dell Power Edge 1600SC servers, 1 x HP DL320 G1, 1 x Compaq 8 port KVM, 1 x NAS (Yes box), 1 x 15" LCD and 1 x Standard BT ADSL Modem. Should I split this between two UPS devices or buy just the one? I also need advice on what to get?

I will be adding a DL380 G5, a couple of DL320s and a second Cisco router for MPLS in the near future but I can then take the Dells off the UPS as they will just be my test systems for updates and the ADSL modem can also be removed from the UPS as if there is no power then is no browsing the net anyway (maybe the lazy users will get some work done!)

The UPS can be free standing or Rack mounted but due to he weight I would rather have it free standing as I think the floor may find it hard to cope with all that weight in one place.

Thanks

[dave87]

I've used both MGE and APC kit, and if I'm honest there wasn't a lot between them. Both did what they had to when the power failed, so I'd quite happily use either again.

Rackmount vs Free Standing, really depends where its going, if the kit is already rackmounted and there is space in the rack, then that would be my suggestion. From memory, when we spec'd ours there wasn't a huge price differential between the two, but that may have changed.

[Jay]

I am more woried about the floor not taking the weight. My last APC unit was so heavy that it took a few of us to lift it into the rack. Also as the rack is already populated I think we would struggle to get it in without toppling the rack over.

I'll talk to construction when I get in, they know what the floor can take and make the changes if needed.

How long did they last when the power failed? what kind of VA am i looking at here as well?

[dave87]

How long did they last? Not sure, as they weren't mission critical (being in education very little was) they were just used to give the servers a chance to shut down properly, and make sure the network in the rack (the main fibre switch) wasn't abruptly shut off.

I can't honestly remember the capacity of the ones we used, but they were fairly chunky. (Enough to power 4x dual processor servers at least, plus networking kit).

APC/MGE have a selector tool on their website here that may be able to help.

[Jay]

Thanks mate.

[burble]

I only buy APC equipment. My former boss bought an MGE UPS for the office in Madrid and after about 6 months it died taking out a couple of HP ProCurve PSU's in the process.

Price wise, I think the APC stuff is a bit more expensive but not massively so. With APC you'll pay more for a rack mounted one but in my eyes it's better to have the UPS in the rack to try and reduce cables running outside the rack. It can also be advantageous to have a heavy UPS sitting at the bottom of the rack to give it more stability.

I'd expect a UPS to be heavy, they've a solid metal box containing dirty great power inverters and lead acid batteries

[peterb]

I am more woried about the floor not taking the weight. My last APC unit was so heavy that it took a few of us to lift it into the rack. Also as the rack is already populated I think we would struggle to get it in without toppling the rack over.

I'll talk to construction when I get in, they know what the floor can take and make the changes if needed.

How long did they last when the power failed? what kind of VA am i looking at here as well?

You need to look at the VA of the connected load and get a UPS that will supply that. The hold up time then depends on the battery capacity, and depends on whether you want to maintain the node during a prolonged power outage, or whether it is to hold teh system up long enough for a controlled shutdown. If it is the latter, a hold up time of about 10 minutes should be sufficient - depending on the make/model/software you can configure how and when it will shut down the system, and optionally e mail you the state.

If you are looking at maintaining the node come what may, then yoiu are in a whole new ballgame - and risk assessment. If it is truly mission cricical and you can't be without it at all, then you are looking at some form of standby generator to take over. This again ranges in complexity from an automatic start and switchover unit for unattended operation, to one requiring manual intervention.. If you dont't expect to get a power failure of more than (say 30 minutes) then a UPS wouold probably be OK.

You need to consider the type of UPS - 2 main flavours - line interaactive and online. Line interactive provides a degree of line regulation, but the inverter is (in simple terms) running in parallel with teh mains supply, and takes over if the main input fails. These tend to be the cheaper/home/small system UPS. An online UPS takes the mains input and uses that to supply the inverter which then supplies all the output load. The input is replaced by the battery if it fails. These are more expensive, but offer betterr line regulation, and the hold up time can be increased by adding higher capacity secondary supplies.

You need to do some research, cal;culations and risk assessment to decide what you need and balance that against what you can afford. You may want to outsource the design and supply to a specialist company that does uniinterruptable power supply solution. As always, Google is your friend.

[Jay]

I'll have a look into it. All I want is for the systems to be able to shut them self down correctly. I have had a disaster in the past when we lost a couple of servers due to a power outage.

[peterb]

I'll have a look into it. All I want is for the systems to be able to shut them self down correctly. I have had a disaster in the past when we lost a couple of servers due to a power outage.

In that case (if it is the server) have a look at the PSU rating in the server concerned and multiply by 1.25 to get a rough VA figure (assuming a power factor of .8 - not unreasonable) do the same for any other peripherals that you want to run off the UPS (routers etc) and that will give you the rating of the UPS (or UPSs) that you require. YOu can probably get away with as little as 5 minutes hold up time, but aim for 10, with shutdown initiated on low battery or after sat 7 minutes (if a breaker trips, it gives time to reset it before the systems shut down.

On line interactive would probably do the job, choose fromAPC, Merin-Gerin or Emmerson Liebert based on specs and price. Any would be OK for that not very demanding requirement.

Remember that batteries don't last foreever and will add to the maintenance schedule. Aim to replace them about every 2 years. You will also need a test schedule to make sure that they do work when you need them! (Say every 3 or 6 months)

[Jay]

I have decided to go for the APC Smart-UPS 2200VA USB & Serial 230V

This version can sit it behind the rack

It will be at about 50% capacity with current hardware, will give us 23 minutes up time in the event of a power outage

SUA2200I - More Images

This product is a rackmount version

Amazon.co.uk: APC Smart-UPS RM 2200VA USB & Serial - UPS ( rack-mountable ) - AC 230 V - 1.98 kW - 2200 VA - 9 Output Connector(s) - 2U: Electronics & Photo: APC

On APC's site its £739.00 but as you can see on amazon its only £414.40

Any clue as to why?

[burble]

Are you getting a network management card too? It's handy to have the UPS on the network so that any servers connected to the UPS can be signalled to shut down if the power goes.

The APC site has always had priced listed that are a way off what you can actually buy the equipment for, no idea why.

[Jay]

I would need one of these cards for each server? I thought the ups connected to the switch.

[burble]

You only need one but the UPS doesn't come with one and I didn't see you mention that you were ordering one, hence why I mentioned it.

[Jay]

hmmm

I thought UPS came with this. Will be needing one of those!

[burble]

Nope, very few APC UPS's come with a network management card. Don't be fooled when you look at the pictures you posted - the RJ45 connector under the serial port is actually the USB port. The UPS comes with an RJ45 - USB cable.

Factor in about £200 for an APC1917 card.

[Jay]

jesus....