[OpenAFS] fine-grained incrementals?

Jeffrey B. Woodward Jeffrey.B.Woodward@Dartmouth.EDU
Fri, 04 Feb 2005 15:31:57 -0500


John S. Bucy wrote:

>On Wed, Feb 02, 2005 at 06:51:13PM -0500, Jeffrey B. Woodward wrote:
>  
>
>>Have you considered using my suggestion (private email reply) of trying 
>>Subversion (SVN) to manage the binary diffs and to attain a "proper" 
>>version management system at the same time?
>>    
>>
>
>I don't have a lot of experience with subversion so far but I'd worry
>about:
>
>1.  How smart is their binary diff?
>  
>
It appears that Subversion uses the vdelta algorithm. You may find the 
references on citeseer helpful: 
http://citeseer.ist.psu.edu/context/372230/0. In addition, RFC3284 - The 
VCDIFF Generic Differencing and Compression Data Format, 
http://www.faqs.org/rfcs/rfc3284.html, may be of some interest.

Googling about yields loads of fun information. In summary, it appears 
from my reading (and comparisons between rdiff and vdelta posted by 
others) that subversion should do at least as good of a good as rdiff.

>2.  I don't really like berkeley db.
>  
>
Many people don't (for varying reasons -- of course)! So use the file 
system file store instead of the Berkeley DB backend: svnadmin create 
--fs-type fsfs {repository_name}

>3.  How well is it going to handle large objects on the wire and in in
>its store?
>  
>
Not sure what you mean by "on the wire", but in it's store you should only be limited by your choice of the backend: Berkeley DB vs. FSFS... You're able to store your rdiff output in your filesystem, so I'd imagine that the FSFS backend would serve you well.

>john
>
-Jeff Woodward