Questions about configuring the AP9631

[BillP]

Controlled early shutdown is when you are trying to load shed with one of our older style UPSs that typically don't have old groups. It also works well when you want the UPS to do things based on certain criteria and you do not have PowerChute Network Shutdown clients. Is this why you're using it? Just want to verify.

1. The best info we have on that for is here-> http://www.apcmedia.com/salestools/PMAR-8P9G2C/PMAR-8P9G2C_R2_EN.pdf (PDF page 41 explains how it works and delays, etc).
2. Yes, that is correct. The one thing I am personally not 100% sure on is if you have your low battery duration match the 9 minutes what exactly happens. Ideally though they should not match if you are trying to load shed with controlled early shutdown. Maybe voidstar might know? My educated guess tells me if anything is selected under Controlled Early Shutdown then that is the type of shutdown that will occur (so low battery duration setting does not really matter) and apply shutdown delay and then do the shutdown.
3. Which ever one happens first will start the shutdown process. Think of them having OR statements between them so like Time on battery is more than X minutes OR UPS runtime is less than X minutes, OR, etc

[Anonymous user]

Awesome. Thanks, Angela. From all the web searches I've done and the discussions on this subject (both in these forums and others), this appears to be one of the great geeky mysteries.

[BillP]

Steve,

OK - For all these questions, let's assume the following: a) the On-Battery event occurs at 12:00AM midnight, and b) the UPS reports 60 minutes of runtime when the event starts, meaning at 1:00AM the UPS will be dead, and c) the PCNS client has no events configured, meaning any shutdown initiation will trigger from the UPS. Let's also assume away any Force Negotiation issues.

1) We all agree that if the Low Battery Duration is 10 minutes, the Low Battery Condition starts at 12:50AM, right? Yes.

2) You said the Command File would execute after 3 minutes have elapsed in the Low Battery Condition (which would be 12:53AM)? Why wouldn't it execute at 12:50AM and be finished at 12:57AM?The command file will execute at 12:50 or when the low battery condition is met. Then after the 3 minutes has elapsed PCNS will command the OS to shut down. If you had configured PCNS to send a shutdown command to the NMC it would do that at this time.

3) At what time does the 2 minute "fixed" delay start in your timeline? In this scenario since you are not sending the shutdown command to the NMC from PCNS there will be no 2 minute fixed delay. The UPS should remain running for the 10 minutes or until the battery runs out.

4) At what time does the user-configured UPS Shutdown Delay begin in your timeline? See question 2.

5) And when does the UPS shut off? It can't be later than 1:00AM... since it will have run out of batteries by then, right? See question 3.

I recommend that you set the low battery duration on the NMC to 5 minutes greater than the total amount of time needed to run a shutdown command file and to shut down the OS.

[Anonymous user]

Hi, Bill. Thanks for the detailed reply. A few follow-ups:

3) At what time does the 2 minute "fixed" delay start in your timeline? In this scenario since you are not sending the shutdown command to the NMC from PCNS there will be no 2 minute fixed delay. The UPS should remain running for the 10 minutes or until the battery runs out.

3a) Is the absence of the two minute delay ONLY a result of the fact that the UPS will be dead at 1:00AM? I suppose another way to ask this question is whether the UPS programatically "acts" any differently if its turn off sequence is initiated by a signal from PCNS vs. initiated by a state where the remaining runtime is less than the Low Battery Duration.

4) At what time does the user-configured UPS Shutdown Delay begin in your timeline? See question 2.

4a) I suppose this is a similar question to my followup above - is the UPS Shutdown Delay (configured on the NMC in UPS / Configuration / Shutdown) programatically ignored if a shutdown signal isn't issued from a PCNS client? Or is it merely non-existent as a practical matter because the UPS would be dead before it would launch?

5) And when does the UPS shut off? It can't be later than 1:00AM... since it will have run out of batteries by then, right? See question 3.

5a) Let's make another assumption that might answer all my above questions in one shot. Let's assume the runtime calibration on the UPS is wrong, and that the UPS reports 10 of runtime remaining at 12:50AM (thereby kicking off the UPS-driven shutdown/turn off process at 12:50AM), but that in reality there's actually enough battery for the UPS to last until 1:15AM. In that case, what would the timeline look like?

- Would the 2 minute fixed delay begin at 12:57AM (when the command file execution time is over) and then the UPS Shutdown Delay (let's say it's 10 mins) begin at 12:59AM, after which the UPS would turn itself off at 1:09AM?

- Or would the the timeline follow the procedure shown on the bottom part of the above graphic -- realizing full well that the graphic is from a PCNS-driven shutdown, and not the scenario we're talking about. So that is to say, would the 2 minute fixed delay begin at 1:00AM (since the Low Batt Duration = 10,  the Command File Execution time = 7, and 10 > 7), and the UPS Shutdown Delay begin at 1:02AM, after which the UPS would turn itself off at 1:12AM?

- Or would the UPS, after sending the OS shutdown signal to all PCNS clients at 12:50AM, just keep running until it dies at 1:15AM?

- Or something else?

I apologize in advance if I'm being pedantic. I'm just trying to be thorough for my article. Thanks!

(edit: Sorry - this post appears way more scrunched up after posting that it did/does in edit more. I apologize if it's hard to read.)

[BillP]

Steve,

3a. The delay does not exist because in this case the UPS has not been command off.

4a. If no shutdown command has been issued then the UPS will run until low battery.

5a. Once the NMC reports low battery PCNS will start the command file, wait the delay time and then command the OS off. The ups would run until the battery is dead.

BTW: what is the article you are writing?

[Anonymous user]

Thanks for the answers.

I decided not to use the Controlled Early Shutdown and spent the experience:

I installed the PCNS utility on several virtual machines and connect them to the NMC. I did not set up the Configure Events and Configure Shutdown on PowerChute Network Shutdown Clients.

After turning off power supply NMC sent PCNS clients command to shutdown their OS, but the time when the PCNS clients started shutdown is a bit different from the calculated value, probably because the load on the UPS was not high.

Do I understand correctly that in my case the UPS must send PCNS clients command to shutdown their OS when the time remaining on battery will be Low Battery Duration + 2 min + Shutdown Delay (http://www.apcmedia.com/salestools/PMAR-8P9G2C/PMAR-8P9G2C_R2_EN.pdf (PDF page 41)), and UPS should turn off after this period of time and it is this period of timeI shouldconsider when planningshutdownthe OSservers connectedto the UPS.

[BillP]

Yes, you're correct but at the low battery duration is when the shutdown signal will go out and then you have those delays built in before UPS turns off.

[Anonymous user]

Thanks, Bill! OK! I finally think (thanks to you and Angela) I understand exactly what happens in the case of a UPS-driven shutdown. Which brings me to what I THINK is my last question!

In the event of a PCNS-driven shutdown (the kind that the graphic explains), I'm looking at the bottom (UPS) timeline, at that first waiting period where it says the longer of Low Battery Duration and Command File Execution time. Assuming the CFE time is 8 mins, and the Low Bat Duration is 10 mins, does that mean the UPS will wait FOR 10 minutes until moving on to the next step (since 10 > 7), or does it mean that the UPS will wait UNTIL 10 minutes of runtime remains before moving on to the next step? The graphic leads me to believe it's the former, which would kind of make the term "Low Battery Duration" a misnomer if you're in a situation (like I am with one of my servers) where you have an hour of runtime available when the system goes on battery, and no Command File. With a Low Battery Duration of 5 minutes, the UPS will turn of relatively quickly... as opposed to if it kept operating until it hit the "5 minutes of battery life remains."

I'm writing an article that's a "60 Minutes" style expose of how underpaid social community personnel are paid for having to put up with demanding forum posters! Hehe - no actually, I'm writing a HowTo guide on my blog (http://stevejenkins.com/) explaining the available options for "smart" shutdown of systems in the event of power loss, and got confused when trying to explain to myself the exact differences between shutdowns that are initiated by the client saying "I've stayed at this party long enough -- I'm leaving" vs. shutdowns initiated by the battery saying "This party is about to be over."

[BillP]

Can I just say I laughed out loud at:

I'm writing an article that's a "60 Minutes" style expose of how underpaid social community personnel are paid for having to put up with demanding forum posters! 

I am sure Bill will too.

My thought on your last question is low battery duration is that it is the amount of time when the UPS defines its "low battery state" which forces a shutdown on everything if it is still up. It will run that amount of time while basically screaming "low battery" at PCNS clients and visually/audibly too. In your scenario with 10 minutes for low battery duration and 7 minutes for CFE, then the low battery state starts with 10 minutes of runtime are remaining and the CFE starts when the OS shutdown starts (which will be when low battery state starts) so the CFE would execute also at the 10 minute mark and take 7 minutes to complete while the whole time the low battery state is still true. Then the UPS should run for three minutes if PCNS client does not tell it to shutdown (which as Bill said is the only time you'll see an extra two minute delay forced).

This is what I got from the conversation Bill and I had the other day. Bill, can you verify my comment?

[BillP]

Hi,

Once the NMC reports low battery PCNS will start the command file, wait the delay time and then command the OS off. The UPS would run until the battery is dead or if PCNS has been configured to do so it will send a shutdown command to the NMC and any delays set will be honored and then the UPS will power down. 

Example: UPS is SMT1000 with 2 switch outlet groups. Each outlet group has a different power off delay. Group 1 has a 4 minutes delay, group 2 or Main is set for 5 minutes. (You always want the Main outlet group delay to be greater than the switched outlet group.) Low battery is set for 15 minutes, PCNS is configured to run a command file that takes 2 minutes, and configured to shut UPS down. When the UPS battery drops below 15 minutes of runtime NMC sends out a signal to all PCNS clients that low battery has been hit. PCNS will start the configured command file, send shutdown command to NMC, and after the command file delay of 2 minutes PCNS will wait an addition 70 seconds before starting OS shutdown. When the NMC received the shutdown command from PCNS it starts the count down for the outlet groups. Outlet group 1 powers down 4 minutes after receiving the signal from PCNS and group 2 powers down 5 minutes later.

If you click on force negotiation with the low battery setting at 15 minutes then both outlet group delays get set to 15 minutes. So in this scenario group 1 will power off 15 minutes after PCNS send the signal and then the 2^nd outlet group will power off 15 minutes later (30 minutes after PCNS sent the shutdown command) or when the UPS runs out of battery.

Hope this helps.

[Anonymous user]

Seriously - thanks for sticking with me.

A couple more questions. First, on the graphic under discussion, on the UPS line where it says "sleep command issued" - is that command issued by the NMC to the UPS, or by the PCNS client to the NMC? If by the PCNS, at what point in its timeline?

I realize now there are multiple options for OS shutdown and UPS turn off, but let's assume we're talking about the exact method described by the graphic under discussion, which is:

• The PCNS client has "Shut Down System" checked for the "UPS: On Battery" event on its "Configure Events" page.
• System goes On Battery. The PCNS client will wait for the number of seconds entered in "Shut down the PCNS operating system only when the event lasts this long (seconds)" which is the Event Shutdown Delay in the graphic.
• On the PCNS "Configure Shutdown" page, the "Turn off the UPS after the shutdown finishes" radio button is selected.
• At the end of the Event Shutdown Delay, the PCNS client will signal the UPS to begin its turn off process ("UPS turn off initiates" on the graphic).
• At the exact same time, two processes commence: 1) the PCNS begins the OS shutdown according to the settings in its .INI file (command file execution time + 10 second delay + 60 second delay, goodnight!) and 2) the NMC begins the UPS turn off process (wait "some period of time" + 2 mins + UPS shutdown delay, goodnight!).

I'm still murky on how that "some period of time" is calculated. The graphic says it's "the greater of Low Battery Duration and Command File Execution Time." Assuming there's 60 mins of battery runtime at the end of the Event Shutdown Delay (when both processes commence), and Command File Execution Time is 7 minutes, and Low Battery Duration is set to 10 minutes, then at the end of the Event Shutdown Delay, does the UPS wait 10 minutes (since 10 > 7) before the 2 mins + UPS shutdown delay?

[Anonymous user]

Thanks for the replies and link. After reading many things became clearer to me.

But I do not have complete understanding of the NMC and PCNS clients.

How to correctly  configure the Network Management Card  so as to ensure maximum runtime of servers that are connected to the UPS?

For example, my server is enough 3 minutes to shut down the operating system. For me it is important that the server was working as long as possible if the power is turned off. What are the ways to set the NMC can I use other than Controlled Early Shutdown, to provide maximum runtime my servers?

In the PCNS client there are events Runtime: Exceeded and Batery: Discharged. I have not found in the user guide more information about them. Can be tell me more about their use?

Thanks.

[BillP]

Controlled early shutdown is typically for users not using PCNS as a way to load shed.

If you're using PCNS, you should not use Controlled Early Shutdown in my opinion.

How many servers do you have? If you just have one (or multiple but they all need the same amount of time to shutdown), the easiest thing to do is to adjust the low battery duration setting on the management card. This is 2 minutes but default. You could raise it to 3 or 5 so when 3 or 5 minutes of runtime is remaining, the UPS will hit "low battery" which forces all PCNS clients talking to that management card to shutdown. Thus, you just install PCNS and don't have to configure anything else there (unless you need a command file to run).

The events in PCNS you're talking about are typically used when you want different servers to shutdown at different time or you want to conserve battery power.

I don't know much about those two events (as I suggest you check PCNS help file for a good description) but they are more so used when that event last for X seconds, then it forces the PCNS client to shutdown before the UPS has been depleted. So, they'd probably be configured when you are doing the opposite of what you wanted (which you said you want to run your server as long as possible).

[BillP]

Controlled early shutdown is when you are trying to load shed with one of our older style UPSs that typically don't have old groups. It also works well when you want the UPS to do things based on certain criteria and you do not have PowerChute Network Shutdown clients. Is this why you're using it? Just want to verify.

1. The best info we have on that for is here-> http://www.apcmedia.com/salestools/PMAR-8P9G2C/PMAR-8P9G2C_R2_EN.pdf (PDF page 41 explains how it works and delays, etc).
2. Yes, that is correct. The one thing I am personally not 100% sure on is if you have your low battery duration match the 9 minutes what exactly happens. Ideally though they should not match if you are trying to load shed with controlled early shutdown. Maybe voidstar might know? My educated guess tells me if anything is selected under Controlled Early Shutdown then that is the type of shutdown that will occur (so low battery duration setting does not really matter) and apply shutdown delay and then do the shutdown.
3. Which ever one happens first will start the shutdown process. Think of them having OR statements between them so like Time on battery is more than X minutes OR UPS runtime is less than X minutes, OR, etc

[voidstar_apc]

I agree with Angela. Shutdown will occur due to the first condition that is met (low battery duration, controlled early shutdown options, PCNS clients). If several are met at the same time, the reported cause will be one of them -- precisely which one is undefined.

Given the choice, you should probably set the low runtime shutdown using the low battery duration because it also drives an alarm if the UPS cannot provide that much runtime.

As a practical example, consider this setup:

- 5 minute low battery duration (shutdown when runtime drops below 5 minutes)

- shutdown when power failure lasts longer than 120 seconds

- new UPS with 8 minutes of runtime at full charge

Every time the power fails for longer than 120 seconds (2 minutes), controlled early shutdown will initiate a shutdown of the UPS. But as the UPS' internal battery ages, the runtime it can provide declines. When the runtime at full charge declines to 7 minutes, both controlled early shutdown or the low battery duration could trigger the UPS to shutdown during a power outage. At 6.9 minutes, only low battery duration will trigger the UPS shutdown. Eventually after the battery's full charge runtime declines to 5 minutes, the NMC will warn that the battery is depleted.

[Anonymous user]

Bump?

[Anonymous user]

We have a couple of new UPS's with 9630 cards; a Smart UPS 1500 and a SMX2200RMLV2U.  I have been searching for hours and just found this EXCELLENT post.  We have always run with the USB interface because there's been one server for each UPS. Open the native OS interface, set the minutes before battery dead condition, and you'e up.  I have been poking at the PCNS for a couple days and really wound myself into a hole.  Most everything is botched up.  I need to start over and I need a SIMPLE "best practices" document, or instructions similar. 

For the first UPS, all we want to do is shutdown two Mac desktops when there is a few minutes left on the battery.  Then when wall power is restored, fire it all back up.  Both Macs are set to boot when powered up.  I think I need the outlet groups to fully power down in order to force this rebooting. We are really lost in all the docs and options.

Anything like this available?

TIA

Greg

[Anonymous user]

Hi, Greg. A "best practices" document is exactly what I'm working on. It's mostly written already, and I'm just waiting on those answers to my June 21 post to finish it up! Bill P. and Angela N. are pretty busy babysitting everyone in here, but I'm confident they'll get to it eventually.

[BillP]

I believe Bill P. is researching as I heard him mention it anyway. He found some confusing info he was trying to sort out for you.

[BillP]

Greg,

If each Mac is plugged into a separate outlet group I recommend setting the NMC low battery threshold to 10 minutes. Set the outlet groups power off delays to 5 minutes (this is assuming your Mac's only take a few minutes to power down). So, what will happen is when the UPS drops below 10 minutes of run-time the NMC will send a signal to the PCNS clients that the UPS has low battery and PCNS will command the OS off. You should configure the PCNS to send a signal to the NMC to power down their outlet group. Once the PCNS clients receives the message that the UPS has low battery at the same time it is commanding the OS off it will also send a signal to the NMC to power down its outlet group. The outlet groups will wait their configured delay times and then power down. Once power is restored to the UPS the outlet groups will power back up and then the Mac's will power up. You can also configure a power on delay for the outlet groups if you like to allow the battery to charge up before the Mac's come back on line.

[BillP]

Steve,

To answer your question about "the greater of Low Battery Duration and Command File Execution Time." the wording is awkward. If we go by "the greater of" then it would be which ever is the largest number. However it also read "Low Battery Duration and Command File Execution Time" so that would be adding the 2 together and neither is always the case. Also as an FYI the info presented in that diagram is for older UPS/UPSlink units and not Microlink units i.e. units with switchable outlets.

Examples of testing with SU700 (UPSlink) with AP9630

PCNS set to shut OS down after UPS on battery for 2 minutes, run a command file that takes 5 minutes to complete, send power down command to UPS, and low battery is set to 10 minutes. At the 2 minute mark of on battery PCNS kicks off the command file, sends power off command to NMC, waits 5 minutes + 70 seconds and starts OS shut down. The UPS waits the 10 minute low battery time, the 2 minutes listed in the diagram before going to sleep. The greater of the 2 numbers was used.

Next example: SU700 with AP9630

PCNS is configured to run command file that has 5 minute delay and to send power down command to UPS. Low battery threshold on the NMC is set to 10 minutes. When PCNS received the low battery signal from the NMC it initiated the command file, sent NMC the power down command, waited 5 minutes plus 70 seconds and then started OS shut down. The UPS stayed up for 16 minutes after receiving the power down command from PCNS. Going by the diagram it should have stay up for 17 minutes. 5 minute delay, 10 minute low battery and the extra 2. Why the discrepancy? There is a plus or minus 1-2 minutes variable.

So if the UPS is UPSlink then the above info is relevant. If the unit is Microlink then the info provided on 21 June is relevant.

I am off starting this afternoon and will not return until 8 July. Enjoy the July 4th holiday!

[Anonymous user]

Thanks, Bill P. You're right - the wording is awkward, particularly since it seems that "Low Battery Duration" is doing "double duty" as a term. That same value is used to determine when a Low Battery Condition occurs (when "Low Battery Duration" minutes of runtime remains), and in cases where there is no Command File, "Low Battery Duration" is essentially synonymous with "Maximum Shutdown Time."

Speaking of which... I stumbled across something today that actually helps answer my original question. I decided to do a test shutdown on an NMC in the UPS/Control tab. I selected "Reboot UPS" and checked "Signal PowerChute Server Shutdown." The very next screen showed this:

and it explains precisely what will happen with all the user-controlled variables -- and basically answers my original question. My Low Battery Duration is set to 8 mins, so the UPS will wait 10 minutes, then wait for my Shutdown Delay, then come back on after my Return Delay. Sorry I didn't find this screen earlier... it would have saved you some hassle.

Still, I learned a LOT from both you and Angela N. in this conversation, and I think I'm ready to finish my blog post now. I'll post the address here when it's done.

Many thanks to you both, and Happy July 4th!

[BillP]

I don't know if I've ever seen that screen myself either but I am glad I know about it now

Looking forward to your blog post and Happy 4th to you too.

[Anonymous user]

Happy 4th to you, too, Angela! How come we're both in the office today??? We should be outside blowing stuff up!

I finished my post about 10 seconds ago. It's a long one (I have a tendency to over-explain), but if you and/or anyone else you hang out with at the APC Mothership come across any errors in the doc, please feel free to point them out so I can fix them.

Here's the link:

HowTo: Configure Low Battery Duration and PCNS to Shut Down with an APC SmartUPS

[voidstar_apc]

I'm impressed; Nice article.

[BillP]

Hi stevejenkins - looking good! I know I take a lot for granted reading our documentation and knowing what it is trying to message but this does a really good job of explaining it to novice users and first timers as well as just people that don't with it too often.

Bill mentioned to this to me after he read it but we were wondering if anywhere you clarified "Smart UPS" and what models exist (knowing there is UPS-Link and Micro-link) and how they may work differently? Seems as though your article is geared towards the older style UPS-link models and I figured maybe you could note that some place.

[Anonymous user]

Great suggestion, Angela. I'll edit and point out the UPS-Link vs. Micro-link differences. You're right - it is geared towards the older stuff, since that's the stuff I use, and there seems to be a lot of it out there.

[Anonymous user]

One more question based on a question I got on my blog:

If there are four PCNS clients attached to a single outlet group, and the three options on the PCNS client are:

1.Turn off this server Outlet Group at the UPS after the shutdown finishes

2. Turn off the UPS after the shutdown finishes (This is dependent on the UPS model and/or shutdown mode enabled for the UPS).

3. Do not turn off UPS.

I'm assuming only ONE of the PCNS clients needs to have option 1 or 2 selected, and the rest of the clients should select option 3. Correct?

And the obvious next question is, does it matter WHICH PCNS client has option 1 or 2 selected? Meaning, should it be the server that shuts down the "slowest" -- or does that not matter?

Thanks!

[voidstar_apc]

If you're not doing staggered shutdowns (instead all servers start shutdown at the same time), the answer is simple:

- Let PCNS know that slower servers take longer to shut down by putting a few minutes in the Script Execution Delay field in PCNS. (Should have double checked the execution timeline -- script execution delay happens before OS shutdown, so unless using a script to shut down things, it won't help with a longer OS shutdown time)

- *edit* Increase the outlet off delay to accommodate the longest OS shutdown time needed by attached servers.

- Set all servers to trigger a UPS shutdown or use load shedding to do so.

If you are doing staggered shutdowns, here are the options. I recommend #3:

1) Staggered shutdown via PCNS + last computer turns off UPS:

- Pros: Easy to set up

- Cons: If power returns after some computers have shut down but before the last computer is triggered, then there's no mechanism to automatically turn those computers back on.

2) Staggered shutdown via PCNS + first computer turns off UPS:

- Pros: Computers will start back up when power returns.

- Cons: All computers must turn off eventually once the first one turns off. Staggering by using the script execution delay to delay later computers turning off is trickier.

3) Staggered shutdown using outlet group (either PCNS or load shedding):

- Pros: Computers will start back up when power returns.

- Cons: Computers that turn off at different times must be plugged into different outlet groups.

[Anonymous user]

Blog post edited to make the distinction clear.

Thanks again for all the excellent help and responses.

[Anonymous user]

Hey, Angela. I'm writing a blog post explaining the difference between PCNS-driven shutdown (based on time since On Battery) vs. UPS-driven shutdown (based on battery time remaining), and have a question about this graphic from the PCNS helpfile:

On the bottom (UPS) timeline, where it says "the greater of Low Battery Duration and command file execution time," I'm still not clear how it decides how long that wait will be. Now, I realize that his graphic is actually describing a situation where the PCNS initiates the shutdown after an Event Shutdown Delay, but my question is actually about a UPS-driven shutdown (and I couldn't find a comparable graphic from you guys for that situation).

Let's assume the following:

- I do NOT have shutdown enabled in PCNS for the "UPS: On Battery" event.

- Command File Execution Time is set as 7 minutes

- Low Battery Duration is set as 10 minutes

- I have 20 minutes of runtime when the UPS loses power

What does that UPS timeline look like?

My best guess is that the UPS runs for 10 minutes, and then enters the Low Battery Condition (because 10 mins of runtime remains). But then how long is that initial waiting period on the UPS, before the fixed 2 minute delay and the variable UPS Shutdown Delay?

This graphic shows that the UPS's first waiting period is calculated by comparing the Low Battery Duration (10 mins) and the Command File Execution Time (7 mins), and selecting whichever value is greater (10 mins).

But if that bottom timeline starts when there's only 10 minutes of UPS runtime remaining, it won't have enough runtime available to wait for 10 minutes, plus another 2 minutes, plus the UPS Shutdown Delay.

So is this graphic accurate for a UPS-driven shutdown?

[BillP]

Hi again stevejenkins,

Such an involved question for a Monday morning!! Just kidding.

Let me see here. Basically, for your example, with 10 minutes remaining (low battery duration), yes a shutdown would start there and it should know that after 3 minutes have elapsed, to execute the command file. Then there should be the 2 minutes extra delay built in (for unforseen circumstances) with the other shutdown delay a user can configure.

For a low battery shutdown, which is what you're calling UPS-driven shutdown, the design is to run as long as it can until it hits low battery (2 mins by default) and then apply shutdown delay, and 2 minutes built in.

BUT! I have force negotiation option defined in the knowledge base and this also is different I believe when you have a UPS without groups versus one that does have outlet groups.

In the knowledge base, (http://www.apc.com/site/support/index.cfm/faq/), look for article ID FA156160. That explains part of what you're asking - can you take a gander and see if its clearer than what I am trying to say?

[Anonymous user]

Hehe - I agree, it's a pretty involved question. Just wait until you see the blog post that I'm working on. Seriously, tho - I really appreciate your help in trying to figure this stuff out. Thx, Angela N.

I'd already read that KB article on Force Negotiation, but as far as I can FN doesn't do anything different than a reboot of the NMC -- meaning the NMC checks each PCNS client to see how long they're reporting they'll need to shut down (based on Command File Execution Time + 10 second OS Shutdown Delay + 60 second OS Shutdown Command length, etc.), picks the slowest client, then adds the user-configured UPS shutdown delay

OK - For all these questions, let's assume the following: a) the On-Battery event occurs at 12:00AM midnight, and b) the UPS reports 60 minutes of runtime when the event starts, meaning at 1:00AM the UPS will be dead, and c) the PCNS client has no events configured, meaning any shutdown initiation will trigger from the UPS. Let's also assume away any Force Negotiation issues.

1) We all agree that if the Low Battery Duration is 10 minutes, the Low Battery Condition starts at 12:50AM, right?

2) You said the Command File would execute after 3 minutes have elapsed in the Low Battery Condition (which would be 12:53AM)? Why wouldn't it execute at 12:50AM and be finished at 12:57AM?

3) At what time does the 2 minute "fixed" delay start in your timeline?

4) At what time does the user-configured UPS Shutdown Delay begin in your timeline?

5) And when does the UPS shut off? It can't be later than 1:00AM... since it will have run out of batteries by then, right?

Based on the answers to those questions, I'll probably have a few more.

Thx!

[BillP]

The one comment I want to make is you are mentioning a low battery shutdown/UPS-driven shutdown yet we are talking about a PCNS client being involved..I will answer the questions based on the scenario you've given but with no PCNS clients at all and strictly going on a low battery shutdown it'd be run as long as possible until low battery duration + 2 minutes for unforseen circumstances + shutdown delay.

1.) Yes, I agree with this.

2.) I guess you're right. I will also hope Bill P. would verify what I am saying when he has a minute but I guess low battery duration trumps any setting and would begin the shutdown process. I guess I am still used to the command file duration taking less than low battery duration and that happening first. So, I believe you're correct. Low battery point starts the entire shutdown process which would call the command file.

3.) If I refer to the timeline, I believe it to be 1:00AM (after the 10 min low battery duration).

4.) Should be 1:02AM after the fixed two minute delay for unforseen circumstances which is also the same time the UPS starts sleeping or counting down its shutdown delay if it has one.

5.) I think its later but then this doesnt seem to make sense when I think about it.

Let me chat it over tomorrow to verify my thoughts on all of these. I got too busy today to go over it and don't want to give you incorrect answers.

[Anonymous user · Accepted solution]

Thanks, Angela. Yes - you're correct. We are indeed talking about a low battery shutdown with a PCNS client being involved. But that's because I can think of TWO different ways that an NMC/UPS and PCNS client can interact to shut down/turn off both the client and the UPS:

a) PCNS-driven: The PCNS client is configured to initiated a client shutdown X minutes after the On Battery Event (that X minutes being the Event Shutdown Delay), and the PCNS client has the radio option checked that says "Turn Off the UPS after the shutdown finishes" on the PCNS client's "Configure Shutdown Page." I imagine people choose a PCNS-driven shutdown who want to preserve battery life on the UPS after shutdown.

b) UPS-driven: The PCNS client is NOT configured to initiate any client shutdown ever, or signal the UPS to turn off. Instead, the battery runtime on the UPS reaches a point where the UPS signals the attached PCNS client to shut down the OS, and then the UPS turns itself off. I imagine people choose a UPS-driven shutdown if they want to maximize the post-on-battery event uptime of their computer system.

I have a very comfortable understanding of the timeline with option 1. It's the timeline with option 2 I'm trying to figure out.

I tested it today, and I know that the UPS can trigger an OS shutdown event on the PCNS client when the unit loses power and the Low Battery Duration exceeds the available runtime  (I tested with a SmartUPS 1500 and AP 9630. I set Low Batt Duration set at 8mins, available runtime was 6mins, and I pulled the plug and the OS shut down gracefully). Hmm... maybe I should do the same test with a stopwatch!

Anyway, addressing the items in your latest response:

3) I'm with you. I also believe it "should" be 1:00AM... but only if the UPS isn't already dead by then... which I'm thinking it would be if the 10 min Low Battery Duration started at 12:50AM.

4) Same issue as #3. If the UPS dies at 1:00AM because it's out of batteries, 1:02AM never comes... sniff, sniff...

5) From your reply to this one, I can see you're exactly where I am: scratching my head and saying "wait a minute... this math doesn't add up..." And that's a GOOD thing, because it means you totally understand my question!

No problem if you got busy. Take your time. I don't have a deadline on the blog post, and I just want to make sure I understand both possible shutdown timelines properly before I publish it.

Thanks and G'nite!