Hello, Being new to this list and to Nut, maybe my question has been asked before but I didn't find a clear answer. My question is : is it possible to make nut aware of the percentage (or duration) of time before the UPS exhausts its power ? Thus making Nut conditionning the shutdown of the servers depending on the remaining load. I saw this thread on the mailing list : http://lists.alioth.debian.org/pipermail/nut-upsuser/2008-July/004252.html But I didn't understood clearly what it means (probably due to my poor english...) Thanks for your help. -- Emmanuel Lesouef DSI | CRBN t: 0231069671 e: e.lesouef at crbn.fr
Citeren "Emmanuel Lesouef" <e.lesouef at crbn.fr>:> My question is : is it possible to make nut aware of the percentage (or > duration) of time before the UPS exhausts its power ? Thus making Nut > conditionning the shutdown of the servers depending on the remaining > load.These are options that some (usually higher end) UPSes have. NUT itself will only support changing the values that set these levels in the UPS, but it will not initiate shutdown at a certain battery level. Both these features require accurate monitoring of the actual battery charge and the load that is supplied by the UPS. Devices that do this both, invariably will already support shutting down when a (configurable) critical battery level or time remaining has been reached. If yours doesn't, it almost certainly will have an entirely battery voltage based charge calculation, which is *not* accurate enough to give a reasonable estimate on the runtime remaining to make this possible. In that case, you'd risk that your UPS suddenly stops because the battery is empty. Best regards, Arjen -- Eindhoven - The Netherlands Key fingerprint - 66 4E 03 2C 9D B5 CB 9B 7A FE 7E C1 EE 88 BC 57
Citeren "Emmanuel Lesouef" <e.lesouef at crbn.fr>:> Is Upssched the workaround to this ? With a trigger to ONBATT, to wait > for several minutes (translated to seconds) until shutting down the > server.If you want to shutdown your systems before the UPS signals a low battery, yes. This may be needed for instance if the remaining runtime on battery when the UPS reports 'low battery' is too short for an orderly shutdown. Reasons may be a very complex (long) shutdown procedure or an exceptionally short runtime remaining (some UPSes will shutdown almost immediately after signalling low battery). But please note however that using 'upssched' to shutdown your systems after a fixed time running on battery is not bullet proof (at all). If the power returns after a power outage and fails again before the UPS battery is fully recharged again, you'd still risk a hard shutdown. Likewise, if over time the battery ages (and capacity is reduced) or the load increases (more systems connected) it will also fail to protect them. The only real solution to the above problem, is getting yourself a UPS that offers both shutdown and restart at certain battery levels and/or runtime remaining. Mine will start the shutdown sequence when battery charge is down to 50% and it won't restart until the batteries have recharged to at least 50%. It will also signal 'low battery' when the remaining runtime (with the actual load) is less than two minutes. Best regards, Arjen -- Please keep list traffic on the list