Re: Dom0 starvs DomU

[dieter roelants <dieter.NetBSD%pandora.be@localhost>]

On Sun, 15 Nov 2015 14:16:46 +0100
tg%gmplib.org@localhost (Torbjörn Granlund) wrote:

> 
> Please understand that I have yet to hit a (NetBSD release x Xen release
> x configuration) where compiling in Dom0 does not make DomU disk
> operations outragously slow.
> 
> The underlying disk speed does not seem to be a factor.  (I used to have
> spinning rust, now most systems run top-of-the-line SSDs.)
> 
> Instead of asking me to try more configurations, please consider trying
> to reproduce this.

A possibly interesting datapoint; I have recently seen (multiple times)
similar symptoms but under different circumstances. The culprit in my
case was a misbehaving web application of which the backend crashed and
the javascript frontend kept on constantly sending requests. This
resulted in firefox hogging the CPU in dom0 and also in ssh sessions to
the domU's being barely responsive. So, no real I/O involved here
(although I guess network access may have been responsible too).

kind regards
dieter