Restic is awesome for moderate operational scale, but when it's got to backup thousands of storage block devices with arbitrary number of files on them, it just doesn't really work.
Is there anything cool people use for Ceph-RBD backups nowadays?
For now, the only thing in the OSS world that doesn't choke at this scale is Benji, but it looks like it's not really maintained anymore, and I worry it may not support newer Ceph versions.