[OpenAFS] UDP slowness remedies?

Dan Pritts danno@internet2.edu
Mon, 25 Oct 2010 16:39:33 -0400

On Oct 25, 2010, at 4:35 PM, Steve Simmons wrote:
> A couple of years ago we did some performance testing on different ssh =
encryption algorithms for bulk transfer to a single host. Forcing use of =
blowfish gave us the fastest throughput. This was at least partially a =
CPU issue; there were upwards of 10 machines dumping data via ssh to a =
single host with the equiv of 'tar cf - ... | ssh -c blowfish hostname =
tar xpf - -C /dirname'. That's close enough to Dan's suggestion that I'd =
expect blowfish to be a win for you.

> Assuming you don't mind the data being viewed in-transit, get the =
Pittsburgh Supercomputer ssh version. It has switches that allow you to =
encrypt the authentication steps but sends the data in plaintext. If you =
do lots of simultaneous instances, CPU is drastically reduced or removed =
as bottleneck.

It also has an encryption algorithm that utilizes multiple cores=20

More importantly, it also fixes the totally broken nature of ssh's =
internal windowing.

If you care at all about ssh performance you should check out their =


Dan Pritts, Sr. Systems Engineer
office: +1-734-352-4953 | mobile: +1-734-834-7224