Venus Pi Expand to Fit SD for Logging

We use the Pi in a few places, mostly pre-sales energy metering and inside pole/mast based systems for monitoring solar/battery via Ve.Direct to MPPT (and hopefully soon using @Louisvdw’s BMS driver once we switch to a supported BMS). One of the issues we are having is that the Pi does not log to disk when the Internet goes down. We’ve tried - on the older sdimg filesystems - to expand the size of the data partition, and it shows in VenusOS as having 10+ GB of free space, but still when Internet goes down, it does not log.

Any idea why?

Related, on the new wic images, when we try resize the data partition, VenusOS tells us the FS is corrupt.

I have a Venus Pi that I am using at home to connect to a BMV in my trolley backup that I have for my home office. We had an internet outage last week where the internet was down for ~12 hours, but there was no gap in the data. At our previous house I had one connected to a Carlo and pretty poor WiFi signal, but the log data will always upload once it’s restored.

I know that if you navigate to Settings > VRM online portal there is a Stored records and Oldest record age which will show how many records there are and the oldest record’s timestamp.

One thing that caught me out was that I turned on the Reboot device when no contact option, but on a reboot the entries aren’t saved, so I turned that back off.

The Pi was flashed with the Venus OS around about June last year and I think I used the files, but it’s on v2.66 at the moment…

Not set to reboot. Oodles of space. But still massive gaps in the data.

Am interested if there is any update on this. We are still experiencing gaps in the data with Venus OS running in rPi.

might be useful to know whether it does not log or whether it looks like it does not log. I played with various verions of VenusOS on a Pi3 and they seemed to log to SD without internet (both the and wic.gz versions - granted I did not try for hours/days of network absence).

any case, I did notice that when not authorising a new version of Venus on VRM that even if the Pi had internet access the date on Venus remained wrong (but it was definitely contacting VRM since VRM would indicate being contacted by an unauthorised device). When manually uploading the log I would then end up with VRM indicating the system was last seen some 53 YEARS ago because the log files would have been date stamped as 1970. If looking back at the historical data on VRM there would then be graph data for 1970.


  1. maybe check the historical data for some of the installations where there are gaps in the data (maybe the loss of internet leads to a date change on the Pi?)
  2. or see what happens if you grab a copy of the log (/data/db/vrmlogger-backlog.sqlite3) before venus tries to upload it when the internet comes back and then manually upload the log to determine if there is empty log vs “misplaced” log.
  3. Another option is to also check whether the gaps are there if using an USB flash drive for storage rather than the SD card (might be safer to any case log to USB to reduce chances of SD card corruption?).

The RPi not having a real time clock causes quite a bit of trouble at times…

Normally, ntp updates the time before logging starts… but in rare cases (especially where internet is poor), it may well send you back to 1970.

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OK, I will do some more testing. Thank you @plonkster and @Village_Idiot !