How do you prevent full battery discharge during power outage?

[BillP]

I have our UPS working and restarting the servers.  When the power goes off, the UPS runs until the batteries are drained.  I would like for the shutdown and the ups to turn off sooner to save battery power.  The reason is, when the electric is off, the users can not work and there is no reason to keep them on.  When the power comes on, we don't want to wait for the batteries to charge.  Obviously, if we turn the ups off sooner, the batteries will have enough charge on them that the UPS will turn on without delay when the power returns.

Can this be done?

[BillP]

Yes, you're correct. It will do the reboot cycle since AC power is present. I apologize for the confusion on the questions

[BillP · Accepted solution]

Last week I ran several test by turning the power off of the UPS and watching the shutdown.  Everything went like I thought I should.  Four server are configured to shutdown after 10 minutes of an on battery event.  The rest are have the default configuration and just shutdown on low battery

Basically the sequence last week was:

1. 10 minutes on battery triggered the shutdown by one of the 4 servers.

2.  The UPS starts a gracefull shutdown and all servers start to shutdown.

3.  The 4 servers with a 120 second wait for command file stay on longer.

4.  All server shutdown

5.  UPS turns off with 50% battery capacity left.

6.  UPS powers on after power restore with no delay for battery charging.

This week I removed 2 of the 4 servers that are set to trigger a shutdown and turn off the UPS.

This happens:

1. 10 minutes on battery triggers just the two servers and they shutdown.

2.  UPS remains on and doesn't start a gracefull shutdown.

So how is the suppose to work?  In one case the on battery event triggered a gracefull shutdown and in the other case it did not.  All 4 servers are configured to shutdown the UPS to save battery power.

The diagram is great, but it really doesn't explain what happens when there are multiple servers running.

Now I am totally confused because the system acted differently with no change in the configuration except for the removal of 2 servers.

[BillP]

I have our UPS working and restarting the servers.  When the power goes off, the UPS runs until the batteries are drained.  I would like for the shutdown and the ups to turn off sooner to save battery power.  The reason is, when the electric is off, the users can not work and there is no reason to keep them on.  When the power comes on, we don't want to wait for the batteries to charge.  Obviously, if we turn the ups off sooner, the batteries will have enough charge on them that the UPS will turn on without delay when the power returns.

Can this be done?

[BillP]

Yes, you can do it. All of our software has a preserve battery type of setting.

Is it PowerChute Business Edition or a Network Management Card and PowerChute Network Shutdown? Either way, which version of each?

With PowerChute Business Edition, you should be able to ultimately do some type of load shedding under the shutdown settings to say shut down this client after X minutes on battery or other similar conditions and then when that client is done shutting down, it will shut off the UPS.

With Network Shutdown, you'd configure this also by setting the UPS: On battery event in each client's Network Shutdown configuration to shutdown the client(s) after the UPS has been on battery for X seconds/minutes. Each client also has a Turn UPS off setting which will command the UPS to turn off after its done shutting down your client - you'd want this to be selected on your last client or the one that takes the longest to shutdown.

It'd be easier to help you with this in more detail knowing your UPS model (from the sticker on the back or front) and the version of software you have. Depending on UPS model and if it has outlet groups or not, the menu options may be different.

[BillP]

UPS is a Symmetra 8000

NMC is a AP9617

Using PowerChute Network Shutdown v3.0.1.

If I understand your message correctly, setting "UPS on Battery" to "Shut Down System" with delay will shutdown the server after so long of being on battery.  The Server with the longest shutdown time should be configured to Turn off the UPS.  For redundancy perhaps all servers with the same and longest runtime should be configured to shutdown the UPS.

If the above is correct, I have the following questions.

1.  If the "Runtime Calibration" puts the UPS on battery, will it signal PCNS and cause the servers to shutdown?  Will any "manual" operation that puts the UPS on battery trigger the "on battery" event and cause the servers to shutdown?

2. If you have the servers shutdown at different times,  say 10, 15, 20 minutes, and the UPS goes on battery for 12 minutes.  The 10 minutes servers would be shutdown, while the 15 and 20 minute servers would be running.  Is there any way to restart the 10 minute servers? Or would all servers eventually be shutdown and then restarted?

3.  Is there a simpler way to reserve 30% battery power and set the Minimum Battery Capacity at 15%?  This way when the power returns, the UPS will turn the servers on when the power is restored instead of waiting for the batteries to charge to 15% of capacity.

[BillP]

Hello,

Yes, your understanding is correct.

1.) No, runtime calibration does not cause a shutdown as that would not be good. Plus, it only discharges a UPS down to between 10-20% and not to a true low battery state no matter your settings. The only way this could happen is if you simulate a power outage or control the UPS from the management card and indicate you want clients to be signaled to shutdown during a shutdown/reboot/off command.

2.) There is no way unfortunately if power is restored before the UPS turns off and completes its shutdown and reboot cycle.

3.) You might need to do a little calculating to figure out how much 30% capacity is in terms of runtime for your UPS load. For this UPS model, I cannot think of a simpler way. Some of the newer model Smart UPS make it a bit easier. I would suggest you do configure the clients that shutdown last, if all at the same time, to turn the UPS off after its done if there is no way one will shutdown before the other. So you'll need to find out your total runtime, how much is equal to 30% capacity and make sure you take into affect the changes that may happen to that calculation when items start turning off so you dont get confused.

[BillP]

I am unclear about question 2.

Recap:  If I have servers to shutdown at 10,15, and 20 minutes for a on battery event .  If a power outage lasts for 12 minutes, the servers set for 10 minutes will shutdown for sure.  Will the 15 and 20 minute servers be shutdown and then the UPS reboot to restart everything?

Here is an alternative and would like to know if this would work:

Set all servers to shutdown with a 10 minute on battery event.  In "Configure Shutdown" set the "The command file need this much time to complete" to delay the shutdown of some (not all) servers.  On the servers with the longest delay, set PCNS to turn off the UPS.  NOW the question is, if the power goes off and turns on in 12 minutes and the servers have started to shutdown, will the UPS reboot and start the system back up.

[BillP]

Sorry, let me clarify.

If the shutdown process has not started on certain servers (because the UPS has not run on battery to hit the threshold of 15 or 20 minutes on battery yet) then no they will not begin their shutdown process and remain on. The servers configured at 12 minutes will proceed to shutdown and assuming the UPS comes back on without a reboot cycle to force a reboot to the servers and their BIOS setting of AC last state, then they will need to be manually started or somehow turned on remotely outside of PCNS or UPS.

Are you asking if the command file delay will remove the requirement for manually starting the servers? Since the command file is part of the shutdown process, you cannot use this to stop the shutdown process and prevent those servers from shutting down.

Here is the shutdown process for reference, taken from the PCNS help file.

[BillP]

No that is not quite it.

According to the diagram, when the command file starts the UPS will initiate a shutdown.  I'm I correct in that the UPS will continue with the shutdown even if the power comes on?  And then will the ups power back up since the power has been restored?