[OpenAFS] Why is speed of AFS loopback adapter set to 10 Mb, even if physical interface is Gb capable?

Holger Rauch holger.rauch@empic.de
Sun, 25 Apr 2010 16:19:51 +0200

Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

Hi Lars,

thanks for your reply.

Lars Schimmer schrieb am Sunday, den 25. April 2010:

> Usual auto negotiation does its job quite good.
> But OpenAFS enables encryption of data transfer on each standard install
> - which results in drastic performance decreases.

Thanks for mentioning this and that's exactly what I'm wondering
about. Encryption too is involved when doing SCP transfers (even
stronger encryption, such as Blowfish or AES 256) and I get scp speeds
of 60 to 82 MB/sec when transferring to native ext3 fs.

So, my question is: Why is there almost no decrease when using SCP
with a strong encryption algorithm (compared to plain DES that AFS
uses) but there is *drastic* decrease in performance with only plain
DES enabled compared to an unencrypted transfer?

> E.g. my workstation client (linux) does 10-12 MB/sec with encryption
> enabled, but >70 MB/sec with encryption disabled.
> My point is on: disable encryption.
> Btw, our linux clients does roughly 20-50 MB/sec so far. Still need to
> test memcache.

Any good ideas as to how to test memcache?

Thanks in advance & kind regards,


Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: Digital signature
Content-Disposition: inline

Version: GnuPG v1.4.10 (GNU/Linux)