(On my iPad so apologies for the brevity. But this UPS decision has been dragging on way too long)

 

I need a UPS obviously. System specs below...and it's clear that I don't need anything major. I just need one to run for 5-10 mins at the most to detect that it's on the battery, before unraid initiates a clean shutdown. Simple.

 

Then I start over complicating things:

• Am I calculating my requirements correctly? Is CyberPower OK to use (I've seen conflicting reports on that front on this very forum)
  
• If I calculate that my build draws 450w at full power (allowing for HDD expansion), what does that mean for my UPS requirement? Is 540w/900vA enough?
  
• If/when I upgrade this build I'll be going for more powerful kit (current i7, 16GB ram (maybe more). Even the most outrageous builds I've experienced with so far say that 650w under load is enough.....but how much more UPS headroom do I need to allow for?
  

 

I picked out this CyberPower UPS which, at 900w/1500vA should be easily enough to run any server I Can think of...and probably run my iMac on it as well (i7, 8GB ram, 512gb SSD). Then I start doubting my calculations.

 

Tldr: my brain is hurting on this topic......help me make sense out of this? Please?

 

 

That model looks adequate. If you don't have your communication gear on battery backup as well, that model should also have plenty of umph for all your switches and routers unless you are running a mini datacenter in your house.

 

The Cyberpower models work fine as long as you plan on letting your gear stay shut down after an outage. The setting that gives issues IIRC is the UPS power off after clean shutdown doesn't reset properly.

 

I don't recommend restarting equipment on power restoration automatically anyway, as recharge times for the battery backup mean you want to be sure the power is going to STAY on after it comes back instead of cutting off again, possibly before the battery has had enough time to recover to allow another clean shutdown.

 

Adding another full machine to use the same UPS has its own set of issues, namely which machine gets the shutdown command, and how does the other machine know to shut down as well. These are mostly solvable issues, but add another layer of complexity.

Appreciate the response. It's a good point about the routers/switches - it may be a case of hooking those up to the UPS (via a 4-way socket most likely) as maintaining the Internet means that my other half can stay on the net if/when there's a power outage. So:

 

- run server for 1 minute of battery. Send shutdown to unraid if still on battery

- maintain router(s) on battery as long as possible. Looks like 50w will be more than sufficient, so a few hours?

 

Assuming that is even possible?

 

I don't need power on once unraid is back on the mains - 99% availability is more than enough for my needs. I just need to make sure that the power requirements are captured correctly, especially in the advent of a server upgrade. Is anyone able to spec out what unraid server would need 900w/1500vA of UPS? Doesn't need to be exact, but it would help confirm my thinking....especially if such a UPS would easily handle a dual Xeon, 64GB ram, 15+ HDDs, extra Sata cards, a few fans...?

In fact the spec listed here would probably meet my needs for years...

 

I just want to confirm that I'm doing the maths correctly here....especially important as it's conceivable that I need to include a GPU as well (I want to run a number of VMs)

 

Edit: since I've started paying attention to what I'm reading - this link seems important: http://outervision.com/b/BBpa0i

 

Can I be confident that Outer Vision's site saying that 800vA UPS is recommended is good enough for my needs? I honestly can't say I've ever noticed that "UPS recommendation" bit before....