@TrystanLea: sda2 is OK on sda3 i get an error “was not cleanly unmounted, check forced”.
Then "error reading block 123132 (Input/output error) while getting next inode from scan. Ignore error?
when i do yes, it askes “Force rewrite?”. when i say yes, it repeats the message but wit the next block 123132 and it keeps increasing the number.
I also tried to copy the phpfina files (after stopping feedwriter manually), 1.dat and 1.meta are ok, but 10.dat crashes the system (it unmounts the sd card…)
I will try if i can copy other files…
The myqsl database is importing ok.
On the new pi the inputs are showing, but with an error where the feed are going, editing that shows the error feed (or feed id) does not exist.
Update: i was able to copy most of the files in the phpfina directory. only 12 files (6 dat and 6 meta files) were unreadable. Making the backup gzip file myself with these files i was able to import it to the new pi 
But obviously , the corrupted feeds were some of my oldest and most interesting datafeeds: main use and solar. The raw input (watts) are still ok, but the kWh feeds were corrupted and as such not imported
Is there any way of telling emoncms to create the kwh data from the old watt data? Or is this only done when a new input is detected?
Another way would be to make a php script that asks for the watt info in the old pi and push it with a data to the new, but there are approx 13 million values per feed (since 2016) so it would take quite some time i guess (1 timestamp at a time…)
update2 : just a thought: would it be possible to make a new phpfina file from the jsons i can pull from the old pi? i’m looking at the source code now, and i think it should be possible, but not sure how…