how to shutdown smt2200 configuring it via network management card

[Anonymous user]

I have an apc smt2200 with a network management card. It has a web server on board from which I can configure how it works. Some servers are powered by that ups and they all have PCNS software which connects to the web server on the ups. I would like to achieve the following behavior of the UPS, avoiding any special configuration on PCNS, but using only the possibilities I have on the UPS itself.

The desired behavior is:

when power fails and the UPS has a run-time of less than x minutes (Low Battery Duration parameter) it sends a low battery signal to the connected clients forcing them to shutdown (this is a default configuration on PCNS). Once the low battery signal has been sent the ups waits a Power Off Delay (specified for the outlet groups and long longer than the server shutdown estimated time) then it cuts the power to the load, no matter what happens in the meantime.
When the above procedure is completed if power returns the ups waits some time to recharge its batteries, then it reconnects the load. Servers are configured to automatically start when power return so they will return online.

I tried more times to achieve this goal but I was unsuccessfully so I'm looking for advices. The major problems I faced are:

• when server shutdowns the load to the ups goes almost to zero so it removes the low battery condition and doesn't switch off the outlets.
• power can return as soon as the ups has raised a low battery signal; servers will shutdown but their power will not be cycled, so they will never return online automatically.

Thanks

Filippo

[BillP]

On point 1, I think this is happening because none of your PCNS clients are telling the UPS to turn off when they're done shutting down. You could configure this on the last client to shutdown so that it turns the UPS off - otherwise, it just runs until it has no more battery time left. So, this will require a setting on at least one PCNS client to command the UPS to turn off when it is done.

On point 2, this is unfortunately the way that it works and a reboot needs to be done one way or another via the normal shutdown/reboot process (which can get interrupted as you noted) or manually by someone who reboots the UPS when power is back to force the power cycle or manually turns the servers on.

[BillP]

On point 1, I think this is happening because none of your PCNS clients are telling the UPS to turn off when they're done shutting down. You could configure this on the last client to shutdown so that it turns the UPS off - otherwise, it just runs until it has no more battery time left. So, this will require a setting on at least one PCNS client to command the UPS to turn off when it is done.

On point 2, this is unfortunately the way that it works and a reboot needs to be done one way or another via the normal shutdown/reboot process (which can get interrupted as you noted) or manually by someone who reboots the UPS when power is back to force the power cycle or manually turns the servers on.

[voidstar_apc]

Two possibilities:

- Have PCNS tell the UPS to shut down OR...

- Try using outlet group load shedding. That will turn off the UPS in response to low runtime remaining. Make sure to un-select "Skip outlet off delays" because the off delays are needed to give PCNS enough time to safely shut down the servers.

[Anonymous user]

About what you say on point 1 I would prefer to configure the ups itself to shutdown because I don't want to make any educated guess on which is the slowest to shutdown but only give them all 5 minutes to execute it. Unfortunately I cannot find any way to achieve this.

[Anonymous user]

Load shedding parameters:

Turn Off Outlet Group when:

power failure lasts longer than X seconds

UPS runtime remaining is less than X seconds

UPS is overloaded

Skip outlet off delay

Stay off after power returns

I could try to put "UPS runtime remaining is less than X seconds" to the same value of "Low Battery Duration parameter", so when UPS sends a low battery signal the outlet start the load shedding procedure.

My doubts are that load shedding procedure can be interrupted by a power restored event or by the change in runtime remaining when some server switch off. If this the case the servers will not experience the power cycle they need to restart.

Besides outlets groups can be configured independently but I read a post according to which main power outlet group behavior and timing is partially linked to the other outlet groups.

There are other parameters which seem promising but they don't do what I expected:

Sequencing

Power Off Delay:    X seconds

Reboot Duration:    X seconds

Power On Delay:    X seconds

Min Return Runtime: X

My goal: after a low battery event happens start an irreversible outlet group power off waiting X seconds (Power Off Delay).

Once it completes and power is returned wait Power On Delay, then power on the outlet group.

Is it possible to achieve ?

Thanks

Filippo

[voidstar_apc · Accepted solution]

setecastronomy wrote:

About what you say on point 1 I would prefer to configure the ups itself to shutdown because I don't want to make any educated guess on which is the slowest to shutdown but only give them all 5 minutes to execute it. Unfortunately I cannot find any way to achieve this.

That's in fact what happens. PCNS sets the outlet's off delay to give itself enough time to shut down. If the default time isn't long enough, you can put more time into the "Script Execution Delay" on the PCNS client. But you're right, you don't need to do it from the PCNS side.

I could try to put "UPS runtime remaining is less than X seconds" to the same value of "Low Battery Duration parameter", so when UPS sends a low battery signal the outlet start the load shedding procedure.

I would personally make the load shedding parameter a little higher than the low battery duration, just to make it clear that load shedding should kick in first. Pragmatically, having the two the same should work also.

My doubts are that load shedding procedure can be interrupted by a power restored event or by the change in runtime remaining when some server switch off. If this the case the servers will not experience the power cycle they need to restart.

The philosophy is once a shutdown starts, it cannot be aborted (except manually). A power restore will not stop a shutdown. Both this approach of using "load shedding" or setting PCNS to turn off the UPS would start a shutdown.

The "low battery duration" didn't work because it's just an advisory signal to tell attached devices they need to shut down. It doesn't actually shut down the UPS. Load shedding will shut down the outlet. After the outlet is off, if power returns, the outlet will turn back on. Power returning before the shutdown completes has no effect on the shutdown.

My goal: after a low battery event happens start an irreversible outlet group power off waiting X seconds (Power Off Delay).

Once it completes and power is returned wait Power On Delay, then power on the outlet group.

Is it possible to achieve ?

Yes.