[Nut-upsdev] snmp-ups shutdowns

Tim Rice tim at multitalents.net
Wed Feb 19 02:04:06 UTC 2014

Hi Jim,

On Tue, 18 Feb 2014, Jim Klimov wrote:

> Hello all,
> I was asked about a proper way to ensure powerfail shutdown of a blade
> server fed off an APC SmartUPS, which is monitored by all hosts over
> SNMP. In particular, they'd like to avoid the "untimely" return of
> utility power - when the OSes are already shutting down, and would
> stay down because the UPS is well-fed now and thus won't power off
> and later power on to boot the servers.
> On smaller systems directly connected to an UPS with a ser/usb cable,
> I remember sending an ups-poweroff signal in the end of the shutdown
> procedure, which effectively rebooted the UPS and its load (if the
> wall power is already back). This required picking an ups model that
> did not stay down in such case, of course.
> Now, with the blade situation - each server might need unpredictably
> long to shut down. It would be inappropriate for the first one to yank
> power off those which are still going down.
> Also, according to the manpage, the snmp-ups driver might not implement
> the shutdown commands at all because "it is run at the time when the
> networking might already be unconfigured" (strange reasoning, not all
> OSes even do that unconfiguration).
> So, I wonder if the list members can suggest a way to signal the
> APC SmartUPS to go down and return if the power comes back or if
> it is already present at the time of UPS poweroff (thus acting
> as a reboot)?
> Also, is it possible to request a delay in such poweroff, i.e. each
> host going down would ask the UPS to poweroff in, say, 5 minutes
> (so that other hosts have ample time to shut down properly) with
> each such signal "restarting" the timer, or perhaps to explicitly
> ask the UPS to cancel pending shutdown and then ask it to do it
> again?
> Can it be done with SNMP or rather some telnet/expect scripting?
> There are no serial ports to connect the UPS directly to one of
> the blade servers...

Seems like a similar user case to ESXi.
If you've got a AP9630 card these notes may be useful.

# APC ap9630 notes:
# Use firmware 6.0.6 or later if you want SNMPv3
# Configuration->Shutdown
# In "Start of Shutdown" section, set "Low Battery Duration" and
# "Shutdown Delay" to get enough grace time for the ESXI shutdown
# Optionally, in "End of Shutdown" section set "Return Delay" to 60 seconds.

Now here are the OIDs (pick one) to actually turn the UPS off
after the shutdown delay.

# reboot gracefully (APC) (stays off until utility power is restored)
UPS_OID=". integer 3"
# turn off UP gracefully (APC) (stays off even if power is restored)
#UPS_OID=". integer 3"

Tim Rice				Multitalents	(707) 456-1146
tim at multitalents.net

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