[OpenAFS] Re: afs vs nfs

Jeffrey Hutzelman jhutz@cmu.edu
Sun, 04 Dec 2005 22:09:36 -0500


On Wednesday, November 23, 2005 04:50:26 PM -0800 lamont@scriptkiddie.org 
wrote:

>
>
> On Wed, 23 Nov 2005, Dan Pritts wrote:
>> This can also be considered a disadvantage.  When using AFS, you are
>> forced to manage your storage the AFS way.  Files are effectively not
>> stored natively on the filesystem, and cannot be accessed via some other
>> method, and must be backed up via afs-specific methods.
>>
>> It works pretty well, but as an NFSv4 presenter put it, NFS is a network
>> filesystem - with AFS you have to swallow the whale of all the other AFS
>> stuff.
>
> I actively do not want files stored natively on a filesystem.  I do not
> want to have to traverse an inode tree in order to do a vos release.
> Since AFS stores volumes already serialized, you can stream that file off
> the disk and across the network much faster than doing the equivalent of
> "tar -cf - . | nc destfileserver | tar -xf -" through a directory
> structure.

Actually, no.  AFS does not store volumes serialized in a single file; that 
would have horrible performance and/or require the addition of a block 
allocation layer.  AFS always stores each vnode in a distinct file; the 
difference between inode and namei is how those files are accessed, not how 
the data is structured.

-- Jeffrey T. Hutzelman (N3NHS) <jhutz+@cmu.edu>
   Sr. Research Systems Programmer
   School of Computer Science - Research Computing Facility
   Carnegie Mellon University - Pittsburgh, PA