13. What’s this about data stale?

It means your UPS driver hasn’t updated things in a little while. upsd refuses to serve up data that isn’t fresh, so you get the errors about staleness.

If this happens to you, make sure your driver is still running. Also look at the syslog. Sometimes the driver loses the connection to the UPS, and that will also make the data go stale.

This might also happen on certain virtualization platforms. If you cannot reproduce the problem on a physical machine, please report the bug to the virtualization software vendor.

If this happens a lot, you might consider cranking up DEADTIME in the upsmon.conf to suppress some of the warnings for shorter intervals. Use caution when adjusting this number, since it directly affects how long you run on battery without knowing what’s going on with the UPS.

Note: some drivers occasionally need more time to update than the default value of MAXAGE (in upsd.conf) allows. As a result, they are temporarily marked stale even though everything is fine. This can happen with MGE Ellipse equipment — see the mge-shut(8) or usbhid-ups(8) man pages. In such cases, you can raise the value of MAXAGE to avoid these warnings; try a value like 25 or 30.