On Thu, Nov 18, 2010 at 7:20 AM, Alan Altmark <[email protected]> wrote:

> Also, a guest's ability to use an OSA is limited by the guest's access to
> the CPU.

Very much. In many scenarios that I worked on, disk I/O throughput or
CPU was the limiting factor. I still recall one case where the
customer did a Hipersockets benchmark showing only a few MB/s. They
were using "scp" to transfer from a guest in one z/VM LPAR to the
other. Both LPARs shared the same (single) CPU and he assured me CPU
was not the bottleneck because both LPARs used only 50% of the
capacity... Obviously they really measured symmetrical encryption and
decryption in openssh rather than Hipersockets bandwidth.

Having real data from the experiment helps a lot, though it's still
not trivial to explain all factors.

Rob
-- 
Rob van der Heij
Velocity Software
http://www.velocitysoftware.com/

Reply via email to