I had some problems with backup restore from old SD card emonSD-30Oct18
I followed instruction how to upgrade to a new emonsd image
I downloaded emonSD-24Jul20 image and wite to a new SD card with balenaEtcher
Then I replaced the old SD with the new one and started raspberry with ethernet connected.
I wated for all update, etc. processes completed.
Then login with a new user registered, connected the old SD to USB port and started restore from USB.
Here I see an error: Can’t connect to database, please verify credentials/configuration in settings.ini. Error message: Connection refused
emoncms was not available after that for some time (1-2 mins).
When I logged in again and went to backup USB, I can see some more detailed log.
Looks like the SD card connected to USB recognised as /dev/sdb with 3 partitions /dev/sdb1, /dev/sdb2 and /dev/sdb3
Import from USB procedure tried to mount /dev/sda, /dev/sdb and /dev/sdc instead.
As a result mount points in /media were empty.
So, I decided to mount manually /dev/sdb1,2,3 in /media/old_sd_boot,root,data,
and then run USB import again
Now it also failed with mounts, but as they were mounted already, then the script migrated data successfully.
After that I unmounted devices manually
Please check attachments for details