tar -c /path/to/data -f Backup.tar
Only back up the data that has changed since the previous backup.
A full backup only occurs when the meta file does not exist.
The meta file is referenced with the -g option:
tar -c /path/to/data -g snapshot.db -f Backup-full.tar
To create the next backup use the same meta file but its own backup archive.
tar -c /path/to/data -g snapshot.db -f Backup-incr-1.tar
The restoration will recreate the original data contents.
you would have to first restore full backup:
tar -xf Backup-full.tar
followed by next backup,
tar -xf Backup-incr-1.tar -g/dev/null
Create a working copy of the initial meta file:
cp snapshot.db snapshot-diff.db
and use it for the -g argument:
tar -c /path/to/data -g snapshot-diff.db -f Backup-diff.tar
Restoring a differential backup only requires the full backup and
the last incremental backup to be restored.