Hi fellow hosters!
I do selfhost lots of stuff, starting from the classical '*Arrs all the way to SilberBullet and photos services.
I even have two ISPs at home to manage failover in case one goes down, in fact I do rely on my home services a lot specially when I am not at home.
The main server is a powerful but older laptop to which i have recently replaced the battery because of its age, but my storage is composed of two raid arrays, which are of course external jbods, and with external power supplies.
A few years ago I purchased a cheap UPS, basically this one: EPYC® TETRYS - UPS https://amzn.eu/d/iTYYNsc
Which works just fine and can sustain the two raids for long enough until any small power outage is gone.
The downside is that the battery itself degrades quickly and every one or two years top it needs to be replaced, which is not only a cost but also an inconvenience because i usually find out always the worst possible time (power outage), of course!
How do you tackle the issue in your setups?
I need to mention that I live in the countryside. Power outages are like once or twice per year, so not big deal, just annoying.
I replace the batteries in my UPS every 18 months, and don’t try to outlast power outages.
I have everything configured to shut down if the power goes down and stays down more than 5 minutes, which is ~20% of the maximum rated runtime. (I’m using repurposed desktop hardware that loves it’s watts as a home server.)
I picked the low number for the reasons you’ve outlined: even if the battery is severely degraded, it’s probably not THAT severely degraded and it’s a safe time span to ride out short hiccups, but still well under the runtime limits so that a safe shutdown can happen.
That and I’ve noticed that, typically, if the power is down for 5 minutes it’s going to be down for way longer than 5 minutes, so it doesn’t matter and I’m not going to have enough batteries to outlast the outage.
Plus lead acid batteries hate being discharged at all. But deep charge cycles are really awful for them.
That said changing batteries every 18 months is a little excessive. Unless your UPS is overcharging the shit out of them they should last way longer than that.
Little bit of A, little bit of B.
I probably go through at least one full discharge cycle a month, if not more because the power around here suuucks. (The NAS goes down, but I leave the network gear up until the UPS dies, because fuck it, why not.)
It’s also a ~10 year old UPS that likes to eat a $25 battery every 18 or so months so I just haven’t really had any justification to replace the whole thing yet since there’s an awful lot of $25 batteries in a new UPS.
Replacing the UPS batteries is required maintenance.
Compare the cost of new batteries to a new UPS and realise it’s the cheaper option.make sure it’s configured for clean shut downs before your battery runs out, auto power up on restoration, and hope it doesn’t happen. you will eventually have an outage that outlasts your batteries.
I have a large string of batteries from an old telco office, that runs my rack for 14hrs (calculated, I shut everything down around this time) and that did not last for the 2-3 day outage we had after a storm. Without a generator, you will inevitably have an outage, but if you are prepared, then you can mitigate any damage. use NUT if you need to shutdown or power multiple devices from one monitored UPS
A UPS is really just for brief interruptions, and to bridge the gap until the generator comes on for extended interruptions. If power is that bad where you live, and uptime is that important, get a generator that comes on automatically when power goes out. Or solar panels and a deep cycle battery array or something.
Two UPSs? Or better 3?
Tbh that is the coolest setup I’ve is the OpenCompute rack with 3 UPSs powering the DC rail for the rack. Otherwise two UPS for servers with two redundant power supplies.
How do you monitor your setup now, have you/can you use NUTS?
