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UPS settings

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I just set up an APC Smart UPS with Network Management Card. Its communicating over network cable and is seen by both my servers. What timing settings do you all use? I want my servers to go down when the power-outage is longer than 10 to 15 minutes. At the moment the settings are at default.

 

Battery Level to Initiate a Shutdown (%): 10

 

Runtime Left to Initiate a Shutdown (minutes): 10

 

Time on Battery Before Shutdown (seconds): 0

 

Turn Off UPS After Shutdown: No Yes 

 

Should the UPS be turned of after shutdown? What effect does this have?

What is the best way to avoid complete rundown of the batteries and prolong life of them?

 

 

 

 

 

 

 

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This all depends on the size of your ups units and the power draw of the devices plugged into them. Without knowing both of those values you cant work out the genuine numbers required.

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This all depends on the size of your ups units and the power draw of the devices plugged into them. Without knowing both of those values you cant work out the genuine numbers required.

 

Ok, so its harder than I thought. The UPS is a SMART UPS 1500 which has my 2 servers in my sig on it. Lets say the power draw of both server is 500W. How would I calculate is then?

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I have mine set for 10 minutes for each of the 3 settings listed and then I have it set to turn off the UPS. This gives me about 15 minutes of runtime before shutdown. I think it is best to turn off the UPS as you don't want to run the battery down to 0 if the power doesn't come back on soon.

 

Gary

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How do these settings interact? Perhaps you may want to set the batterylevel to 60% at which the server powers down. Or perhaps the Runtime to 60 minutes? Whichever comes first. And should I set both servers the same?

 

A battery level of 10% or a runtime of 10 minutes on a 1500W UPS might drain the batteries too much.

 

But what does Time on Battery accomplish? Does a setting of 0 disable it?

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In general, assuming you have ample capacity to support it, you want the time on battery to be the driving force as to when the UPS software will shut down the system.    This keeps you from discharging the battery too low -- and provides a reserve in case there are multiple outages.

 

I always set my system to shut down after 10 minutes (time on battery) ... I've found this will keep things running for most outages; and when they're longer than that they are often MUCH longer.

 

The shutdown percentages will override the time-on-battery => i.e. if you set it to turn off when the battery level reaches a certain percentage (10%, 20%, etc.) then it will immediately initiate a shutdown at that level.    So if your load is too high to run for the time you've set for time on battery; the unit will still shut down before the battery is exhausted.

 

MOST systems are drawing far less than the capacity of the UPS, so 10 minutes is a reasonable time;  but if you're drawing 50% or more of the rated load, you should probably set that to 5 minutes.

 

r.e. turning off the UPS =>  Yes, you should do this.  When you set this parameter, the UPS will turn itself back on when power is restored.    This lets you setup your system so it will automatically come back online when power is restored -- you simply need to set the BIOS power options so the system is "always On" when power is applied.

 

There IS a "Catch 22" to this automatic power-on setup:  If the power is restored AFTER the PC has shut down but BEFORE the UPS has turned off, then the system won't reboot ... since it never lost power.  On the rare occasions when that happens, you'll either need to press the power button, or send a WOL Magic Packet to wake up the system.

 

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One thing to remember that the time you enter is not the actual runtime of the UPS battery.  It is how much runtime you want to leave on the battery before it shuts down.

 

For example,

Battery Level to Initiate a Shutdown (%): 10

means that the UPS will run until 10% battery life is left.  I have mine set at 75%

 

Runtime Left to Initiate a Shutdown (minutes): 10

means that the UPS will run until 10 minutes of battery life are left.  I have mine set to run for 10 minutes, my battery at full load would normally last about 40 minutes so my setting is set at 30.

 

Time on Battery Before Shutdown (seconds): 0

means how long you want the UPS to run on battery, normally for a non-smart UPS that can't read how much time it has left.  Setting it to 0 means it is disabled.  I have mine set for 600, 10 minutes.

 

Turn Off UPS After Shutdown: No Yes 

I have mine set to off.  Normally in my area if the power is off for 10/15 minutes, it will be hours/days before it comes back.

 

So based on my settings whichever of the 3 happens first it will shut down.  For me, my UPS should normally run about 10 minutes on battery before initiating a shutdown of my server and then powering off the UPS.

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One thing to remember that the time you enter is not the actual runtime of the UPS battery.  It is how much runtime you want to leave on the battery before it shuts down.

 

For example,

Battery Level to Initiate a Shutdown (%): 10

means that the UPS will run until 10% battery life is left.  I have mine set at 75%

 

Runtime Left to Initiate a Shutdown (minutes): 10

means that the UPS will run until 10 minutes of battery life are left.  I have mine set to run for 10 minutes, my battery at full load would normally last about 40 minutes so my setting is set at 30.

 

Time on Battery Before Shutdown (seconds): 0

means how long you want the UPS to run on battery, normally for a non-smart UPS that can't read how much time it has left.  Setting it to 0 means it is disabled.  I have mine set for 600, 10 minutes.

 

Turn Off UPS After Shutdown: No Yes 

I have mine set to off.  Normally in my area if the power is off for 10/15 minutes, it will be hours/days before it comes back.

 

So based on my settings whichever of the 3 happens first it will shut down.  For me, my UPS should normally run about 10 minutes on battery before initiating a shutdown of my server and then powering off the UPS.

 

 

Thanks. Yes, this sounds very plausible.

The first time I read the manual I interpreted some things wrong because English is not my first language.

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One thing to remember that the time you enter is not the actual runtime of the UPS battery.  It is how much runtime you want to leave on the battery before it shuts down.

 

For example,

Battery Level to Initiate a Shutdown (%): 10

means that the UPS will run until 10% battery life is left.  I have mine set at 75%

 

Runtime Left to Initiate a Shutdown (minutes): 10

means that the UPS will run until 10 minutes of battery life are left.  I have mine set to run for 10 minutes, my battery at full load would normally last about 40 minutes so my setting is set at 30.

 

Time on Battery Before Shutdown (seconds): 0

means how long you want the UPS to run on battery, normally for a non-smart UPS that can't read how much time it has left.  Setting it to 0 means it is disabled.  I have mine set for 600, 10 minutes.

 

Turn Off UPS After Shutdown: No Yes 

I have mine set to off.  Normally in my area if the power is off for 10/15 minutes, it will be hours/days before it comes back.

 

So based on my settings whichever of the 3 happens first it will shut down.  For me, my UPS should normally run about 10 minutes on battery before initiating a shutdown of my server and then powering off the UPS.

 

 

Thanks. Yes, this sounds very plausible.

The first time I read the manual I interpreted some things wrong because English is not my first language.

 

Just be very careful that you replace the batteries on a very regular basis.  As the get older, they have fewer and fewer AmpHours reserve available even at full charge.  (Remember what happens to your car battery in an older car!)  A number of years ago, I had a old battery fail to provide power for more than a few seconds of actual computer operation.  (Luckily, it was windows computer and there were no open files or data in the write cache.)  unRAID servers are not as forgiving to this type of shutdown.

 

I have the 'Time on Battery' set to 30 seconds.  Remember, it takes up to a couple of minutes to shut an unRAID server down from the time the process is started.  I have found if the power is out as long as 30 seconds in my part of the world, it is not coming back on with run time provided by any UPS that I can afford.  And I want my server to shutdown to the power-off condition long before the battery runs out of mojo!  If on some future occasion, the power might all be out for only five minutes, it only means that I had make a unnecessary trip to the basement to restart the servers instead of possibly having to deal with a server with one or more data disks with file structure errors!

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One thing to remember that the time you enter is not the actual runtime of the UPS battery.  It is how much runtime you want to leave on the battery before it shuts down.

 

For example,

Battery Level to Initiate a Shutdown (%): 10

means that the UPS will run until 10% battery life is left.  I have mine set at 75%

 

Runtime Left to Initiate a Shutdown (minutes): 10

means that the UPS will run until 10 minutes of battery life are left.  I have mine set to run for 10 minutes, my battery at full load would normally last about 40 minutes so my setting is set at 30.

 

Time on Battery Before Shutdown (seconds): 0

means how long you want the UPS to run on battery, normally for a non-smart UPS that can't read how much time it has left.  Setting it to 0 means it is disabled.  I have mine set for 600, 10 minutes.

 

Turn Off UPS After Shutdown: No Yes 

I have mine set to off.  Normally in my area if the power is off for 10/15 minutes, it will be hours/days before it comes back.

 

So based on my settings whichever of the 3 happens first it will shut down.  For me, my UPS should normally run about 10 minutes on battery before initiating a shutdown of my server and then powering off the UPS.

 

 

Thanks. Yes, this sounds very plausible.

The first time I read the manual I interpreted some things wrong because English is not my first language.

 

Just be very careful that you replace the batteries on a very regular basis.  As the get older, they have fewer and fewer AmpHours reserve available even at full charge.  (Remember what happens to your car battery in an older car!)  A number of years ago, I had a old battery fail to provide power for more than a few seconds of actual computer operation.  (Luckily, it was windows computer and there were no open files or data in the write cache.)  unRAID servers are not as forgiving to this type of shutdown.

 

I have the 'Time on Battery' set to 30 seconds.  Remember, it takes up to a couple of minutes to shut an unRAID server down from the time the process is started.  I have found if the power is out as long as 30 seconds in my part of the world, it is not coming back on with run time provided by any UPS that I can afford.  And I want my server to shutdown to the power-off condition long before the battery runs out of mojo!  If on some future occasion, the power might all be out for only five minutes, it only means that I had make a unnecessary trip to the basement to restart the servers instead of possibly having to deal with a server with one or more data disks with file structure errors!

very helpfull advice, thank you.

 

We also have a reliablepowernet. The last outage Is already a few years ago. But appliances can sometimes malfunction and activate a power breaker. Thos are usually remedied in 5 to 10 minutes. I probably set the time on battery to 300-600.

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With the 2 servers connected and all drives spundown apcupsd shows a load of 15.6% and a time left of 105 minutes. I guess these are readings given by the UPS? Is there a way to improve the accuracy of these readings?

 

With all drives spun op on the main server (20 drives total) this is 25.3% and 68 minutes.

With all drives spun op on the test server (8 drives total) this is 20.1% and 87 minutes.

With all drives on both servers spun up (28 drives total) this is 29.9% and 58 minutes.

 

So I guess Time on batteries can be set to 600 second.

 

Are there any ways to test the batteries true capacity and runtime?

 

 

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... Are there any ways to test the batteries true capacity and runtime?

 

Unplug the UPS and see how long it lasts  :)

... If you've got the shutdown set to occur at perhaps 10% battery capacity the systems will shut down okay, but you'll then know how long you can really run.    The projections shown by the UPS software are, in my experience, NOT very accurate.

 

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Are there any ways to test the batteries true capacity and runtime?

One way is to use a dummy load instead of your server.  If you estimate the power draw of the server when idle at (say) 100 watts, then with the server disconnected from the UPS you could power 100 watts of light bulbs (use traditional ones, not CCFL or LED types).  Then just see how long it takes before the lights go out.  That way, you can test for any particular load situation until the UPS gives up, or until it reaches a setting that you've set with apcupsd, for example.

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Just a reminder though, the SLA batteries in your UPS do not like to be fully drained, it shortens their life.  It's true that fully draining it with an appropriately sized load is the best way to accurately determine its capacity and run time, but it also makes APC very happy!  The more you do it, the sooner you will have to buy an expensive battery or full UPS replacement.

 

For the same reason, it's best not to allow a power outage to run it down too far.  It's my understanding that most power outages last less than 2 minutes, and after that the odds of returning to full power are roughly the same for 10 minutes, 10 hours, or 10 days (should check that though, my memory is not good).  I prefer 3 minutes for my own devices.  In my opinion, a good number is between 2 and 5 minutes.

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Just a reminder though, the SLA batteries in your UPS do not like to be fully drained, it shortens their life.  It's true that fully draining it with an appropriately sized load is the best way to accurately determine its capacity and run time, but it also makes APC very happy!  The more you do it, the sooner you will have to buy an expensive battery or full UPS replacement.

 

For the same reason, it's best not to allow a power outage to run it down too far.  It's my understanding that most power outages last less than 2 minutes, and after that the odds of returning to full power are roughly the same for 10 minutes, 10 hours, or 10 days (should check that though, my memory is not good).  I prefer 3 minutes for my own devices.  In my opinion, a good number is between 2 and 5 minutes.

 

You are of course correct - the complete drain should only be done for establishing the potential run time.  Most users would advocate only allowing the batteries to discharge maybe 20 - 30% in the event of a power failure.  That way, if the power does come up again but only briefly, there is the possibility of a second successful shutdown.  Depending on local conditions, frequency of power failures, system usage needs, etc., the actual duration can be adjusted as needed.

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