I'm running 9.10 server and trying to automate backup to a USB drive attached to the server. My crontab line is this:

00 4    * * *   root    rsync -rout --modify-window=1 /home/ /media/"My Book"/backup/
My expectation is that this will run every day at 4 AM and copy the contents of /home to /backup on the USB drive. The rsync part of the line runs from a command prompt but with errors because it can't change groups on the USB drive which is formatted FAT32. But that does not keep anything from being copied over. It appears not to run at all as a cron job. What am I doing wrong/