Getting CPIO to output backed up content to a file

Hi, I have a CPIO command set up as follows: find /home/usr -depth -print | cpio -ocvB -O /dev/st0 > backup_log While this backs up my data for the /home/usr directory as requested, and the file backup_log created, this backup_log file is never populated with the backed up information? What am I doing wrong??? I have even tried >> (i think thats apending) the information into an already created fiel with the attributes of 766! Please somebody help. DB