I recently moved our family’s personal storage from a ~14 year old QNAP TS-219P NAS to a new Synology DS224+ NAS, with roughly 2x the storage. The data migration went pretty smoothly, after a couple of false starts. I tried a “restore from USB drive” approach first. After all, both NAS types can back up to ext4 filesystems, so it should read OK, right? Unfortunately these copies take a looong time to complete, and the web UI provides no measure of progress to give confidence that it’s working.