i also do not like to generate weewx reports to RPi’s SD card so i mount weewx/public_html on tmpfs - reads and writes to RAM only. being tmpfs (RAM) the content is lost on reboot, but it is all generated again anyway, just adds some milliseconds to the first reports after a reboot
phillip could generate files and FTP as much as he likes, all the files would be in RAM, not the SD card
requires an entry like the following added to /etc/fstab (all one line)
tmpfs /opt/weewx/public_html tmpfs rw,nodev,nosuid,noatime,noexec,size=10M 0 0
where put your own weewx/public_html location instead of the one above.
it will only take effect next reboot so to make it happen now, after changing /etc/fstab, run
$ sudo mount -a
it might complain about files already existing in your weewx/public_html directory (on SD). it is harmless to mount over them; they will be hidden underneath. but it would be cleaner to stop weewx, remove the files in weewx/public_html on SD, mount tmpfs on weewx/public_html, start weewx again
and don’t worry about the ‘size=10M’ option - that is the *maximum* memory it can use. it only uses as much as it needs