pcns and mnc2: please help with correct mnc2-settings!

[Anonymous user]

Hello!
My situation is:

1 esxi host, running multiple vm`s, vcenter va and pcns va (all on the same host) ( i have another esxi server in the cluster, but this server is turned of most of time and just for testing and not connected to the ups).

1 smart ups smt750i with mnc2.

I configured the pcns va to use vcenter server, configured vm priorization (first, i measured the time, each vm needs for a shutdown, seperated the vm`s into priorization groups and added the time of each vm in 1 priorization group. this added time i wrote into "set VM Shutdown duration" for High, Medium and Low in pcns). The times are:

High: 80 seconds

Medium: 30 seconds

Low: 25 seconds

un-priorized: 30 sconds (this group is empty).

vCenter Server VM Shutdown Duration (under Virtualization Settings) is 240 seconds.

total: 405 seconds. (about 7 minutes)

I also configured a shared local user on esxi-host and vcenter that is used by pcns to access vcenter and esxi. at last, i configured the event "UPS on Battery" with 1800 seconds of delay. in my understanding, that means that after half an hour on battery, pcns start shutting down vm`s and host.

so far so good, but what totally confuses me is are the settings in the nmc2 under Configuration --> Shutdown (i have already read through different articles i googled, but i am too stupid to understand);

In them manual of the nmc2 is written, that the "Low battery Duration" is the time the ups waits when on battery, before turning off (itself). in my mind that makes no sense, because this would mean that the ups could turn itself off before the event "UPS on battery" in pcns reaches the configured delay time. i guess i am misunderstanding something here.

"Basic Low battery Duration" is said to be the time remaining in the battery that signals a low battery condition. i guess that means, that for example, if i write 1200 seconds in this field, that means, that when there are only 20 minutes of battery power left in the ups, a low battery signal is triggered (to pcns).

"Maximum Required Delay": no idea what this is. in my case, it is alway the same as my "Low Battery Duration", after i press "Force negotiation". 

"Sleep time": also no idea.

can someone please explain this to me in SIMPLE WORDS (so that every idiot gets it). 

i attached a screesnhot of the "Shutdown configuration" of the nmc2 at the moment (decreasing the  "Low battery Duration" always leads to "Available runtime has been exceeded." in pcns event log. also attached the settings in pcns 

and: could it be, that the "Low Battery Duration" mus tbe at least (in my case) the 405 seconds plus 2 minutes (about 9 minutes total)? but why does 10 minutes lead to "Available runtime has been exceeded" then? i just dont understand the dependencies?

please help, i am going nuts about this 

[BillP]

Hi,

The NMC help file list the description of 

Low Battery Duration

A runtime remaining threshold, below which a low battery condition is triggered on the UPS. For example, if the Low Battery Duration is set to ten minutes, and the UPS predicted runtime remaining reaches ten minutes or below, a low battery condition is triggered. If input power is not restored to the UPS, it will turn off when the battery has exhausted.

For your setup as listed you should set low battery duration at 12 minutes to allow everything to power down properly in the event the UPS reaches low battery. If the UPS runtime falls below 12 minutes the NMC will send a signal to PCNS tell it to start shutting down the computer. In your setup PCNS will put the host into maintenance mode, shutdown the VMs, shutdown vCenter, take the host out of maintenance mode, PCNS vm will power off, host will power off. See Application Note 180 for more information. 

Description of Maximum Required Delay

• It is the longest shutdown delay needed by any server listed as a PowerChute Network Shutdown client.
• It is calculated whenever the management interface of the UPS turns on or is reset, or when the Force Negotiation option is selected and you click Apply.

Maximum required delay is the delay needed for any computer the is running PCNS and register with the NMC to shutdown. Example: Server is configured to run a command file that need 15 minutes to complete prior to power down and the OS need another 2 minutes to shut down. The maximum required delay would then be 17 minutes to all the command file to run and the OS to power down. 

Description of Basic Low Battery Duration

For a UPS on battery, this defines a runtime remaining threshold, below which a low battery condition is triggered on the UPS. The UPS will then:

• Display the low battery notification on the UPS display.
• Send the low battery notification from the UPS to connected devices via the simple signaling cable.

If input power is not restored to the UPS, it will turn off when the battery has exhausted.

Basic low battery duration will only affect computer that are connected to the UPS using a simple signaling serial cable. It has no affect on PCNS.

Description of Sleep

Defines how long the UPS sleeps (keeps its output power turned off) when you use the "Put UPS To Sleep" option of the "Control" menu. 

The control menu is found in the NMC web interface. 

On 5/15/2018 1:40 PM, Florian said:

i configured the event "UPS on Battery" with 1800 seconds of delay. in my understanding, that means that after half an hour on battery, pcns start shutting down vm`s and host.

That is correct. After the UPS has run on battery for 30 minutes the shutdown process will start. You should be sure that the UPS has the proper available run time to wait the requested 30 minutes plus the needed 12 minute to complete the shutdown process. If it does not you should decrease the delay. 

[Anonymous user]

hi,

to go to the procedure step by step: here you see the stages i am confues about:

- power failure

- ups is on battery 

- after 30 minutes (as configured in pcns), the shutdown-process of the vm`s (including vcenter and pcns-va) starts.

- after another approximately 7 minutes (the time i configured for shutdown in vm priorization in pcns) all vm`s and vcenter and pcns-va are powered down.

- after another 2 minutes the host is powered down (not sure about this: i just think thast this could be the 2 minutes delay mentioned in the manuals)

- ups is still on, waiting  to reach the "low battery duration" time (which i set to 12 minutes). but why does this 12 minutes have any meaning for pcns then? all vm`s and host are shutdown already.

the maiin understanding problem for me is the dependecy between the 1800 seconds delay configured in pcns and the 1 2minutes low battery duation in nmc2. i mean, if the ups has enough power to keep things up on battery for about 80 minutes as displayed on the unit`s screen, and i configutred the shutdown for the on-battery-event with an delay of 1800 seconds (30 minutes), then it will never reach the 12 minutes threshold. so it it useless. 

not really understood the whole thing yet...

[voidstar_apc]

There are multiple ways to trigger the UPS to shut down. The first one to trigger "wins".

- You can configure PCNS to send a shutdown signal to the UPS.

- You can set the low battery duration.

- On many UPSes you can use load shedding to automatically shut down outlets.

As your battery ages, its runtime decreases. 80 mins is a lot of runtime, but some customers may reach a point where they no longer have enough runtime to reach their "time on battery" threshold and still safely shut down. Low battery duration ensures the shutdown occurs while safe shutdown is still possible. If the battery ages to the point where runtime is below the low battery duration, the NMC generates an alarm.

[Anonymous user]

thanks, now it is clear.

[voidstar_apc · Accepted solution]

Apologies, one mis-statement in my earlier message:

Low battery duration will not (by itself) cause the UPS to shut down. It only informs the attached servers running PowerChute that they need to shut down. PowerChute then safely shuts the servers down and optionally sends a shut down signal to the UPS.