Actually, I believe OS X does this for small files in order to not burn a whole filesystem block on a sub 1k file.<p>&quot;In Mac OS X Snow Leopard 10.6, HFS+ compression was added. In open source and some other areas this is referred to as AppleFSCompression. Compressed data may be stored in either an extended attribute or the resource fork.[13] When using non-Apple APIs, AppleFSCompression is not always completely transparent.&quot;<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;HFS_Plus#History" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;HFS_Plus#History</a>