> Then if I copied this file no blocks would be copied until they are written. > Hence the two files would use the same blocks underneath. But specifically > that copy would be fast. Since it would only need to write some metadata. > But when I copy the file: > time cp 10G 10G2
cp without arguments still does a regular copy; btrfs does nothing to de-duplicate writes. "cp --reflink 10G 10G2" will give you the results you expect. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html