I'm noticing false positives for power failures via my UPS in my syslog. Any ideas what would be causing this? Is it something to be worried about? They almost always coincide with disk spin downs, but not 100% of the time.

 

The log entries look like this:

Jul  7 08:22:55 Bunker kernel: mdcmd (117): spindown 0
Jul  7 08:22:56 Bunker kernel: mdcmd (118): spindown 8
Jul  7 08:22:57 Bunker kernel: mdcmd (119): spindown 29
Jul  7 11:41:23 Bunker apcupsd[9954]: Power failure.
Jul  7 11:41:25 Bunker apcupsd[9954]: Power is back. UPS running on mains.
Jul  7 16:10:55 Bunker apcupsd[9954]: Power failure.
Jul  7 16:10:57 Bunker apcupsd[9954]: Power is back. UPS running on mains.
Jul  7 16:43:49 Bunker apcupsd[9954]: Power failure.
Jul  7 16:43:51 Bunker apcupsd[9954]: Power is back. UPS running on mains.
Jul  7 19:08:00 Bunker autofan: Highest disk temp is 36C, adjusting fan speed from: OFF (0% @ 0rpm) to: 160 (62% @ 1506rpm)
Jul  7 19:20:06 Bunker autofan: Highest disk temp is 37C, adjusting fan speed from: 160 (62% @ 1480rpm) to: 170 (66% @ 1591rpm)
Jul  7 19:25:09 Bunker kernel: mdcmd (120): spindown 3

 

The snippet shows no correlation between spin downs and the power failure (separated by hours)

 

It looks like the power did happen to glitch at those times, and the UPS dutifully switched over to backup power.   Power may not have been off long enough for your clocks in your house to start flashing, but the UPS did switch over to battery, waited a couple of seconds for the power to stabilize and then switched back to mains.

I'm sure we're not losing power this frequently. Even 2 second power drops would leave noticeable evidence. This is happening multiple times per day, sometimes when we are home.

 

Also worth noting that my UPS sounds an alarm when the power goes out and I haven't heard it.

 

Your UPS may be sending those messages when the voltage ranges outside a threshold, even though it can correct through AVR and doesn't need to switch over to batteries. There is a wide range of voltage that can be boosted or bucked to ok levels with a good quality UPS. I'm not sure acpupsd makes a distinction (or can) between a full failure and a line correction event.

 

Your house wiring may be borderline inadequate, and events like the HVAC compressor kicking in may be sagging the voltage enough to make the UPS complain, especially if the neighborhood is under power stress to begin with.

Aha. That actually made me realize that we have a laser printer that definitely pulls the voltage down (lights dim) when it kicks on to print. The UPS/server is in the same closet as the printer. I'll do a test to see if printing triggers the message. 

 

I guess there's nothing really wrong then, but ideally I'd get more current to that room...