Archiving CD Images on Irix

At least how *I* archive my images. This creates a .dd file which is 
a faithful representation of the disk which can be reburned and a 
normal copy of the file.

# dd if=/dev/dsk/dks1d3vol of=/sgi/image/$PartNumber_$DiskName.dd bs=16384
# mkdir /sgi/dist/$PartNumber_$DiskName
# cd /CDROM
# tar cBf - . | ( cd /sgi/dist/$PartNumber_$DiskName/ && tar xBpf - )