I use to back up sshfs in the backup_dir_mount.sh and backup_dir_umount.sh scripts. Backup takes place on a remote server. I often have a problem with umount reporting that the device is being used and therefore will not be unmount I do not know if for this reason, but some web backups are too old. How to solve this problem or force ispadmin to run the backup immediately when it is known that it did not happen and was not expected the next backup period?
