Backup to dvd

[David Berg <dberg@cpinternet.com>]

Need some help hammering out a tar/mkisofs command to backup my disks to
dvd.  I'm looking to burn two root level directories (/home,/var and
/usr, /) to they're own dvd.  Problem is I don't have room to build the
tarball or iso on the hard disk before I burn it.  Using a command such
as 

mkisofs -R -o backup.iso /home /var 

looses some directory structure
and if I use graft points I loose directory ownership & permission
information.  At least I haven't yet figured out how not to.  I also
can't figure out how to make mkisofs read from stdin for its directories
so that I can have tar pipe its output directly to mkisofs.  

I'd rather use just mkisofs and have each individual file than one tarball
but I don't want to run into any problems with restoring from backup
either since I plan on doing it shortly (only using half of harddrive
and fdisk for some reason won't let me put a partition on the rest)

Any help would be greatly appreciated.  


Thanks

Dave