OS X 10.6 (Snow Leopard) HFS+ File Compression

Tony tonyt57 at gmail.com
Wed Oct 28 05:43:50 MDT 2009

When rsync 3.0.6 copies files with HFS+ File Compression, the new  
extended attribute decmpfs is not preserved, and the UF_COMPRESSED  
flag is not set on the destination and the destination file is not  

I examined the destination file as described in ars technica  (with ls  
and xattr from a 10.5 Leopard boot), and the compressed data is moved  
from the resource fork to the data fork, and the extended attributes  
'@' are removed from the file.

As far as I know, only ditto in 10.6 can handle HFS+ File  
Compression.  (I even tested a 'clone' with disk utility (file copy,  
not block), and it also failed (block copy, of course works).

On Oct 27, 2009, at 7:39 PM, Matt McCutchen wrote:
> What kind of special treatment from rsync were you expecting?  I read
> http://arstechnica.com/apple/reviews/2009/08/mac-os-x-10-6.ars/3 , and
> as far as I can tell, the compression is handled entirely by the
> filesystem with no intervention from applications needed.
> -- 
> Matt
> On Tue, 2009-10-27 at 19:31 -0400, Tony wrote:
>> Are there any patches (or planned updates) to rsync v3.0.6 to handle
>> the HFS+ File Compression that Apple introduced with Snow Leopard?

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