OpenAFS.org have NOT YET RELEASED any AFS OpenAFS client installer built 
for OSX 10.10.

The 1.6.6 release is known to have problems with 10.10.  The OpenAFS
client integrates with the operating system at a sufficiently low level
that it is very unlikely to work with a different major release of OSX.
If working directly with RStor is a 'must-have', we recommend NOT 
upgrading to Yosemite yet.

-- 
Richard Brittain,  Research Computing Group,
                     IT Services, 37 Dewey Field Road, HB6219
                     Dartmouth College, Hanover NH 03755
[log in to unmask] 6-2085