[OpenAFS] Memory cache question

[Dan Pritts]

On Fri, Nov 08, 2002 at 03:29:12PM -0500, Derrick J Brashear wrote:
> > I would look at using the rsync command to maintain a local disk replica
> > copy of
> > the whole 1gb of images files. Don't mess around with 500 mb. Disk is cheap.
> > The rysnc command is "clever" because it only copies what it has to copy.
> > If there are no changes, rsync will copy nothing.
> 
> Which is clever but has the "not in-band" problem.

rsync can work in-band, copying from one filesystem to another.  It would
not whack the cache, since by default it just compares sizes on the
files rather than comparing the contents.

when implementing this sort of thing, be sure to be smart about it.
Do something like using rsync's "--max-delete" option so that if the
source tree is unavailable (say, because afs where are you are copying
from is broken) rsync does not happily delete all the stuff you are
mirroring, at the exact time that you actually need the local mirrored
copy.  "--max-delete" may or may not be sufficient for your application.

Do not ask how i know this.

danno
--
dan pritts                                       danno@internet2.edu
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