Sparse
From DWIKI
Links
HOWTO
Check sparse file
Compare:
ls -lh myfile du -sh myfile
Or
dd seek=10G if=/dev/zero of=sparsetest bs=1 count=1 status=none du --block-size=1 sparsetest du --block-size=1 --apparent sparsetest
If these outputs are very different, sparse is supported :)
Copy sparse file
rsync -S