Backup foul-up... user error I suspect

New Roon core version 1.4 Build 294 on Sonic Transporter i5, 1TB USB HDD library (content less than 500KB) connected directly, control 64bit iPad, players Oppo 2054kUDP (and remote Monitor audio airstream speaker) via squeezebox streamers.

I was trying to back up the database. I plugged in an empty formatted SSD 500KB to the Sonic T. Selected the appropriate drive ( as I thought ) and requested manual back up. It seems that I didn’t select the drive properly somehow as the back up, I think , has been attempted to the root drive in the SonicT …it failed as the drive quickly became full. The SSD remains empty.

I will try again paying more attention to the drive mounting and selection options or perhaps I will just go for Drop Box as it is easy, but will the full root drive matter …will it compromise Roon ? If so how do I get rid of the errant material?