UPS with Gentoo support

abduct · Apprentice Joined: 19 Mar 2015 Posts: 215

Hi, I was planning to purchase a UPS for my new workstation and I was looking at https://www.amazon.com/CyberPower-CP1500AVRLCD-Intelligent-Outlets-Mini-Tower/dp/B000FBK3QK

I found two ways to communicate with the UPS, one via https://forums.gentoo.org/viewtopic-t-1041668-start-0.html using the power control panel software via cyberpower, the other using NUT https://wiki.gentoo.org/wiki/NUT.

The first has all the features built in, UPS monitoring, server shutdown, email notifications, etc. The later doesn't come with that built in that I can see.

So my question is: Is there a way to script NUT to allow for email notifications, shutting down the system cleanly when it detects a power failure after a timeout grace period, etc

If not I will have to play around with the closed source applications cyberpower provides and attempt to install it from the provided ebuild.

Does anyone recommend some decent quality for the price UPS for home workstation use?

Thanks.

russK · l33t Joined: 27 Jun 2006 Posts: 665

I have an APC very similar to the CyberPower one you link to that I have been quite happy with, but the CyberPower has so many reviews and questions answered on Amazon that it's probably not a bad choice.

https://networkupstools.org/index.html
The features page says it can do SMS and email. I don't use NUT so I don't know. I'm usually sitting right at my computer when the power goes out, I don't need a notification

your application may be different.

Cheers

John R. Graham · Posted: Fri Aug 31, 2018 10:54 pm Post subject:

Hi abduct,

NUT can be scripted to do anything. Pretty easily, too. If you're in the US, I would check out http://www.refurbups.com/ and get an APC ups. Have had very good luck with this supplier (and with APC).

- John
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Fitzcarraldo · Posted: Fri Aug 31, 2018 10:59 pm Post subject:

If you are not particularly wedded to CyberPower, I have found that APC UPSs work with machines running Linux. The open-source APC UPS Daemon apcupsd is available for Gentoo (sys-power/apcupsd) and it can send email notifications, shut down the system cleanly when it detects a power failure after a timeout grace period, and so on.

Are you looking for a'standby/backup' UPS or a 'line-interactive' UPS? The former type will not supply power to the machine if the battery dies (i.e. fails for good) while there is mains supply; the latter will still provide power to the machine if the battery dies while there is mains supply. Anyway, APC sell both types. APC style their standby/backup models as 'Back-UPS' and their line-interactive models as 'Smart-UPS'. As you would expect, the Back-UPS models are cheaper than the Smart-UPS models. apcupsd can be used with both types, but you need to check the specification for each model to make sure.

I use an APC Back-UPS to protect a 24/7 server which is running apcupsd and sends me e-mails for various reasons (loss of mains power; return of mains power; battery low; shutting down the server; etc.) and it shuts down the server if battery power falls below a user-specified threshold (there are different thresholds -- see the apcupsd User Manual for details). In retrospect, for a 24/7 server I should have bought a Smart-UPS rather than a Back-UPS, as the UPS battery died in its second year while there was mains power supply, and power was cut to my server. (Fortunately no damage to the data on the server, but I happened to be away on a work trip and could not replace the 12-volt lead-acid battery until I returned home a couple of weeks later).
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abduct · Apprentice Joined: 19 Mar 2015 Posts: 215

Thanks for the replies!

I am not partial to cyberpower, although I have heard from a friend that works with them saying that they caught fire a few times. Although who knows if this was a off chance or defective product. I will look at that refurb UPS site though.

Price is an issue though. I am looking for something in the 100-200$ range so the cyberpower fit that budget.

As for the smart-ups/backup-ups, if I had to choose a smart UPS may be the way to go. My main thing is I want to allow my server to gracefully shutdown during a power outage to protect my software raid arrays. This is for my home server.

The features I need specifically is graceful shutdown and email alerts. Anything extra is bonus. If I could script the support myself that would be bonus as I could customize features for myself.

Is there a central repo for NUT examples somewhere? Is it a generic API for gathering information, or does it change depending on which drivers you load?

Thanks again.

Akkara · Posted: Sat Sep 01, 2018 5:50 am Post subject:

Here's something that is not directly addressing your question, but is something to consider. It regards battery life.

UPSes run their batteries very hard, and that is why they only last a year or so. Because of that, I generally advise to get a UPS with a much longer run-time than you expect to need. This does two things: first, it's draining the battery slower, which helps it last longer. Then, as the battery starts to degrade, you can delay replacing it because of the extra capacity.

Ideally, the max discharge rate out of a sealed lead-acid battery should not exceed the so-called "1C" rate. "1C" is when the amperes being drawn, equals (numerically) the rated amp-hours of the battery. (And even that rate is considered quite high.) So a 9 amp-hour battery, being discharged at 9 amps, is being discharged at the "1C" rate. A 9 amp-hour, being discharged at 9 amps, you'd expect to last an hour, but the reality is closer to 30-40 minutes. That's because a battery's rated amp-hour capacity is measured at a much smaller discharge, usually 1/10th or 1/20th of that (where the battery would last close to 10 or 20 hours). The faster you discharge a battery, the less "amp-hours" you can get out of it.

If you discharge faster than "1C", the runtimes drop very quickly. Looking at the datasheet for your UPS, it shows 11 minutes runtime at half load (450 W), and 3 minute runtime at full load (900 W). If it were a linear relationship, the full-load runtime would be half of 11, or 5.5 minutes.

It is losing almost 50% of the battery capacity going from half-load to full-load. This tells me the battery is highly overtaxed. Looking at page 2 shows it uses two 12V, 8.5 amp-hour batteries. 12V * 8.5 A-H is 200 watt-hours of rated battery capacity. But 900 watts * 3 minutes is 45 watt-hours. Less than 25% of the battery capacity is actually available to power the machine. The rest is being wasted in inefficiency and heat and causing damage to the battery.

This is not to say it is a bad UPS. Just don't listen to its advertised ratings. If you want low-maintenence longevity, this UPS is fine for loads of 150 watts or less. If your server draws more than that, I strongly advise getting a more capable UPS.

You mentioned a pretty tight budget early on. For a small low-power server you should be fine. But if it has a lot of disks and draws a lot of power, I don't know if you can achieve this ideal on that budget. Either be prepared to replace batteries after every 2nd outage (I'm not kidding here - find out how much replacement batteries will cost - you'll need 2 of them according to that datasheet). Or try to scrounge up a big cheap used UPS that's in good shape electrically, then buy new batteries for it and enjoy a long service life. It is easily possible to go 5-6 years between battery changes, if designed and spec'ed well. Good luck!
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steve_v · Guru Joined: 20 Jun 2004 Posts: 388 Location: New Zealand

abduct · Apprentice Joined: 19 Mar 2015 Posts: 215

Thanks for the information Akkara and steve_v. I did see the specs of the UPS and felt it was a bit low, but I was not expecting hours of runtime, just enough to shutdown. Although I am going to start searching for used UPS and perhaps I can score a better one.

A place where I work throws out UPS's regularly due to batteries going dead (they make too much money to be inconvenienced to just repair the UPS's so they recycle them and buy new). Has anyone tried replacing the batteries themselves or used batteries not rated for the UPS?

I have heard of people putting car batteries and such on a UPS (externally mounted/wired) vastly increasing the amp hours a UPS can provide. I wouldn't be against the idea since this is for my home network, although I don't know if this is actually possible. I would of imagined that the UPS would have a micro controller programmed to a specific rating of battery for protections. But if the charging and such simply checks the voltage to tell when the batteries low/finished charging then I don't see why such a mod wouldn't work.

What is a decent amp hour rating I should be looking at. I am going to run a Dell T7600 4 HDD, dual CPU workstation off it as a headless server (which will power down after a timeout period such as 30-90 seconds to save the raid array) which will be mostly IDLE. Considering my OLD rackmount draws about 250w running ancient hardware (dd2 etc) I can imagine this server drawing around 100-200w idle. Then the only other constant load would be a modem and wifi router, just for my homes occupants convenience. I imagine after the server is such down that the modem and router would draw barely anything.

steve_v · Guru Joined: 20 Jun 2004 Posts: 388 Location: New Zealand

Akkara · Posted: Mon Sep 03, 2018 6:43 am Post subject:

NeddySeagoon · Posted: Mon Sep 03, 2018 9:33 am Post subject:

steve_v · Guru Joined: 20 Jun 2004 Posts: 388 Location: New Zealand

bunder · Bodhisattva Joined: 10 Apr 2004 Posts: 5934

I have 3 of that model of UPS, but they had another display design than the one they're currently using.

abduct · Apprentice Joined: 19 Mar 2015 Posts: 215

@bunder What software is that?

I got myself a free UPS (APC XS1300), but I think the batteries may be shot. I will have to do some investigation and trouble shooting on it. Worse case I spend 50-70$ on new batteries + interface cable and/or recycle it and keep looking for one.

bunder · Bodhisattva Joined: 10 Apr 2004 Posts: 5934

upsc is part of nut.
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