Migrating Nextcloud snap to another system

I’m planning on switching the OS on my Raspberry Pi 4 from Raspbian Buster to Ubuntu 19.10. All of my data are stored in an external drive.

My plan is to run snap run nextcloud.export -abc. Any idea how big the exported data will be?

It’s impossible for us to know, but with those flags it will be a subset of /var/snap/nextcloud/current, so it will be smaller than the size of that directory. Try running:

sudo du -sh /var/snap/nextcloud/current/