On Tuesday, March 14, 2017 at 11:03:54 PM UTC+2, mwall wrote: > > On Tuesday, March 14, 2017 at 2:08:39 PM UTC-4, Theophanis Kontogiannis > wrote: >> >> Exactly this is is the use case but goes down to hard disks standby. >> >> The data base is installed on a RAID5 which during day time does various >> IOPS during about 60% of the time, but during night is idle almost 95% of >> the time, hence the disks get parked and the power consumption goes down to >> 25W total (compared to 70W when disks are spinning). >> >> Running weewx every five minutes means that the data must be written in >> the data base. >> > > thank you for the explanation. > > when the driver polls the station, it asks only for the current values; > polling_interval controls how often the driver queries for current data, > not historical records. > > weewx has no mechanism to say "read historical data every x > minutes/hours/days"; the driver only reads historical data when weewx > starts up. > > And this makes everything crystal clear.
What I though was happening: "run every polling_interval and fetch all previously non fetched data. So thankful for your continuous follow up that shorted things out. > fine offset 10xx/20xx/30xx stations send data no more frequently than 48 > seconds (so you could use polling_interval of 48 seconds instead of 60, if > you want) > > on the hardware, archive_interval determines how often the hardware > aggregates 48-second readings into records. in weewx, archive_interval > does the same thing, but it also determines how often reports will be > generated. > > services that upload data from weewx may be tied to loop data (the > 48-second readings) or archive data. > > so if you do not need weewx to be running continuously during the time > when you want the hard disks to sleep, you could start weewx in the > morning, let it run normally during the day, then stop weewx when you want > the hard disks to spin down. that would make weewx read the archive data > from the station from overnight, then weewx would do record generation > during the day, then the weather station would record data overnight until > weewx starts up again the next day. > > The second solution you suggested bellow looks more preferable in my environment. You see the root filesystem is on high end CF cards running on RAID 1, so it is fast, with steady low consumption, and available continuously day and night. "you might consider having weewx run all the time, but send its data to a sqlite database on a tmpfs (ramdisk)." Any guidance on what to look for to implement it? > that would mean you only get updated reports during the time that weewx is > running (during the day). > > m > -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
