Will rsync copy extended attributes, ACLs, etc. reliably enough for Time Machine?
Rsync, with the -E option, will copy the extended attributes and ACL of a file. The man page for rsync states:


  
    -E, --extended-attributes   copy extended attributes, resource forks
    
    -E, --extended-attributes
                  Apple-specific option to copy extended attributes,
                  resource forks, and ACLs.  Requires at least Mac OS X 10.4
                  or suitably patched rsync.