Move influxdb to an SSD on a Raspi4

OH3.2 on Raspi4.
I would like to make influx to write the db to an SSD attached to my Raspi4.
I formated the SSD with exFAT on a PC and mounted it on the Raspi at /media/usb. It stays there after reboot and I can write to it.
I created the 3 influxdb specific folders under media/usb and edited the influxdb.config file so that instead of /var/lib it uses /media/usb. I changed nothing else. Upon reboot, it would not write any data and all charts remained empty. (I did set Influxdb as default in OH). The folder OPENHAB was not created under …/data. I added that one too, but it did not help.(Swapping the influxdb.config file back to the original one made everything work again with the defaults locations)
Is there another file that I need to edit for OH&Influx to write the data to that SSD?
(I had ZRAM installed but removed it later. Once Influx has found its new place I will enable it again w/o influx))

You did a restart of the influxdb service ?
Does the serivce run after restart ?
Any logentry entry in directory /var/log/influxdb/?
What about sudo journalctl does it show any error message related to influxdb ?

I simply restarted (after a sudo shutdown). Does that kill and restart influx with the new config? I had errors in the OH log saying that influxdb had a problem writing data which the charts showed. I will switch back later and report the error in detail… The /var/log/influxdb folder is empty.
I somehow believe it is an OH error, as it intialises Influx once I add it with openhabian-config. and somewhere there is still a setting somehow refering to this intial setup.

same here. Just wanted to make sure that in case there is an error in that directory it is taken into account. This then means in case of any error you can inspect it using the journalctl command.

influxdb is a service. That means OH does not know anything about where influxdb stores the files. OH communicates with the service via ports.

Hi Joachim,
Did you ever get a solution for this? I wanted to do the same and have the same problem.
Regards Will van Gemert

Hello,
I moved OpenHAB to an external SSD using the SD card only for the initial boot on the Raspi. I do have enough space now for Influxdb. Just moving the influxdb to an external storage device did not work for me.

That’s not supported in openHABian so it now means you effectively no longer run openHABian or your setup is at risk with any openHABian change.

I’d use openHABian to install influx, disable ZRAM for it (edit /etc/ztab) then make the directory from ztab which is where Influx is installed (I think /var/lib/influx) a link to your SSD.

Ok, I have check. I simply used the openhabian setup menu to do that, certainly did not fiddle around.