I''m looking for any bit of info that any of you may have to help improve performance to Dom0/U''s. Performance is fine as long as the host doesnt have much going on but if you have a few domU''s eating a good amount of resources it will cause the latency to go up. Right now i''m seeing a 30-60ms increase in latency. Host is a Dual Xeon with HT disabled. Dom0 is assigned both cpu''s while domU''s are given 1 cpu and distributed evenly between cpu 0 and 1. -- ~Shaun _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
buw20031220@bayern-mail.de
2006-Jun-01 09:43 UTC
Re: [Xen-users] ways to help improve network performance
Did you try a pci passthrough of the Networking cards. Usually these servers are having dual nics at least. You leave one for dom0 and another one is being passed to the most time-critical domU ? Winfried Zitat von Shaun <mailinglists@unix-scripts.com>:> I''m looking for any bit of info that any of you may have to help improve > performance to Dom0/U''s. Performance is fine as long as the host doesnt > have much going on but if you have a few domU''s eating a good amount of > resources it will cause the latency to go up. Right now i''m seeing a > 30-60ms increase in latency. Host is a Dual Xeon with HT disabled. Dom0 is > assigned both cpu''s while domU''s are given 1 cpu and distributed evenly > between cpu 0 and 1. >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Pasi Kärkkäinen
2006-Jun-01 10:28 UTC
Re: [Xen-users] ways to help improve network performance
On Thu, Jun 01, 2006 at 02:21:27AM -0700, Shaun wrote:> I''m looking for any bit of info that any of you may have to help improve > performance to Dom0/U''s. Performance is fine as long as the host doesnt > have much going on but if you have a few domU''s eating a good amount of > resources it will cause the latency to go up. Right now i''m seeing a > 30-60ms increase in latency. Host is a Dual Xeon with HT disabled. Dom0 is > assigned both cpu''s while domU''s are given 1 cpu and distributed evenly > between cpu 0 and 1. >I did these steps to improve network performance with xen 3: 1. Assigned one CPU (hyperthread) _only_ for dom0 2. Changed the (default) xen scheduler to BVT 3. Changed the default linux io elevators from anticipatory -> cfq -- Pasi _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> 1. Assigned one CPU (hyperthread) _only_ for dom0I did this with my initial testing but in the end i disabled HT because i was told it would hurt performance. Somthing about each HT shares the same cache. Anybody have more info on this?> 2. Changed the (default) xen scheduler to BVTCan this only be done by adding sched=bvt to the boot option or can it be done some how on a live running host?> 3. Changed the default linux io elevators from anticipatory -> cfqwhen you build dom0 and domU did you set both to cfq or just domU? ~Shaun _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users