The backup appears to have finished on nodus, and I've put the rsync job back in the crontab.
I removed the rsync backup from nodus' crontab temporarily so as to not have multiple backup jobs running. The job I started from yesterday was still running. Hopefully the backup will finish by Monday.
The line I removed was:
0 5 * * * /opt/rtcds/caltech/c1/scripts/backup/rsync.backup