I've used ssh to localhost as a hack for a backup-to-external-drive script (using Borg iirc) where I wanted the source reading and backup writing to be done as

I've used ssh to localhost as a hack for a backup-to-external-drive script (using Borg iirc) where I wanted the source reading and backup writing to be done as different users. There may have been a more elegant solution but it worked well enough