I know this thread is old, but I ran across it in a search. I use a tool called dar (http://dar.linux.free.fr/ http://dar.linux.free.fr/) that is along the line

I know this thread is old, but I ran across it in a search. I use a tool called dar (http://dar.linux.free.fr/ http://dar.linux.free.fr/) that is along the lines of tar, but with extra features for dealing with multi-volume backup sets and diffs easily. It lets you extract a catalog from the backup set that you can use locally as a checkpoint for doing diff/incremental backups. The catalog is really small, mine is ~10Mb for hundreds of thousands of files. ## here is the initial backup: backing up /nas to ## an archive set /mnt/usb/nas on a usb device dar -R / -c /mnt/usb/nas -g nas ## extracting the catalog from the backup and ## saving it under my home directory dar -A /mnt/usb/nas -C /home/dan/backup/nas-catalog ## I use the local copy of the catalog in my home folder ## when doing diff backups to another mounted usb device dar -R / -c /mnt/usb/nas-diff -g nas -A /home/dan/backup/nas-catalog