I just ran into this. I didn’t realize my restic repos on B2 haven’t pruned in a year, and with v0.9.6 and b2 connections set to 20 it is going to take ~48 hours for the prune to delete 195,885 packs. That’s around 0.8 del/sec like you said. Total prune time is going to be 3-4 days on a 10 gbit connection.