Re: troubleshooting I/O performance bottleneck

[manu%netbsd.org@localhost (Emmanuel Dreyfus)]

Manuel Bouyer <bouyer%antioche.eu.org@localhost> wrote:

> probably not that much, but it's noticeable.
> Did you have something else doing I/O when you did your test, like
> a parity rewrite ? systat shows raid0 almost 100% busy in both cases,
> and for almost the same data transfer rate.

There is no background disk activity.

Running systat vm on both dom0 and domU at the same time while
performing the dd in domU indeed shows identical throughput to disk,
around 15-20 MB/s

When dd runs on dom0, I the throughput is around 30-35 MB/s, so the
difference si significant.

-- 
Emmanuel Dreyfus
http://hcpnet.free.fr/pubz
manu%netbsd.org@localhost