[OpenAFS] Some questions (Linux-oriented)

Derek Atkins derek@ihtfp.com
11 Mar 2002 11:41:09 -0500

Frank Baumgart <frank.baumgart@esc-electronics.de> writes:

> Dear developers,
> 1) are there plans to bring the AFS client into the official kernel
> source?

Which "official" kernel source?  I highly doubt that Sun is going to
pull OpenAFS into Solaris, nor is SGI going to pull it into IRIX, IBM
into AIX, Compaq into Tru64, etc..  No, I'm not trying to diminish
your question, but OpenAFS works on a score of various OSes and
versions, so your question is poorly scoped.  I presume you mean
"Linux", but nowhere do you actually mention Linux explicitly.

Basically, this is a _HARD_ problem to solve.  I've actually spoken to
a number of people about this.  The AFS kernel sources wind up
bringing in about 2.5MB of sources.  I'm not convinced that it's worth
bringing in that much data when the sources are easily compiled
against your own kernel are built by the various distributions.

> 2) are there plans for an in-kernel (opposed to modular) AFS client?


> 3) how stable is AFS?
>    Esp. in an environment where the same data is served with AFS and
> Samba.

AFS is fairly stable.  However, you cannot serve the same data through
both AFS and Samba unless your Samba Server is an AFS client.  The reason
is that AFS, unlike NFS, does not export files from the local file
system.  AFS stores files in special FS inodes that don't give you
access through the normal file system.

> 4) are there any benchmarks comparing AFS and NFS? (postmark, bonnie,
> dbench)

There may be.  A lot depends on what you are trying to do, and what
features of AFS (or NFS) you turn on.  For example, do you turn on
network data encryption in AFS when performing your tests?  Do you
read from the same file multiple times (to test the benefits of the
client cache)?  Are you testing multi-site file sharing and data

There are many reasons to use AFS over NFS, but as for testing
benchmarks, what are you testing for?

> 5) does AFS work on any native filesystem, esp. Reiserfs and ext3?

The AFS Server can use any native file system.  The AFS client for
Linux only works with an ext2 cache.

> Thanks for your answers,

You're welcome.  I suggest you browse the www.openafs.org web site,
and in particular the Wiki of AFS lore.

Good Luck,

> Frank Baumgart


       Derek Atkins
       Computer and Internet Security Consultant
       derek@ihtfp.com             www.ihtfp.com