I tried with 'notsc divider=10' (since it's 64 bit guest), but the results are the still same :-(. The guest is idle at the time of testing. It has 2 CPU and 1024 MB RAM available. On Mon, Aug 16, 2010 at 11:35 PM, Dor Laor <dlaor@xxxxxxxxxx> wrote: > On 08/17/2010 12:22 AM, Alex Rixhardson wrote: >> >> Thanks for the suggestion. >> >> I tried with the netperf. I ran netserver on host and netperf on RHEL >> 5.5 and RHEL 4.5 guests. This are the results of 60 seconds long >> tests: >> >> RHEL 4.5 guest: >> Throughput (10^6bits/sec) = 145.80 > > At least it bought you another 5Mb/s over iperf ... > > It might be time related, 5.5 has kvmclock but rhel4 does not. > If it's 64 bit guest add this to the 4.5 guest cmdline 'notsc divider=10'. > If it's 32 use 'clock=pmtmr divider=10'. > The divider is probably new and is in rhel4.8 only, it's ok w/o it too. > > What's the host load for the 4.5 guest? > >> >> RHEL 5.5 guest: >> Throughput (10^6bits/sec) = 3760.24 >> >> The results are really bad on RHEL 4.5 guest. What could be wrong? >> >> Regards, >> Alex >> >> On Mon, Aug 16, 2010 at 9:49 PM, Dor Laor<dlaor@xxxxxxxxxx> wrote: >>> >>> On 08/16/2010 10:00 PM, Alex Rixhardson wrote: >>>> >>>> Hi guys, >>>> >>>> I have the following configuration: >>>> >>>> 1. host is RHEL 5.5, 64bit with KVM (version that comes out of the box >>>> with RHEL 5.5) >>>> 2. two guests: >>>> 2a: RHEL 5.5, 32bit, >>>> 2b: RHEL 4.5, 64bit >>>> >>>> If I run iperf between host RHEL 5.5 and guest RHEL 5.5 inside the >>>> virtual network subnet I get great results (> 4Gbit/sec). But if I >>>> run >>>> iperf between guest RHEL 4.5 and either of the two RHELs 5.5 I get bad >>>> network performance (around 140Mbit/sec). >>> >>> Please try netperf, iperf known to be buggy and might consume cpu w/o >>> real >>> justification >>> >>>> >>>> The configuration was made thru virtual-manager utility, nothing >>>> special. I just added virtual network device to both guests. >>>> >>>> Could you guys give me some tips on what should I check? >>>> >>>> Regards, >>>> Alex >>>> -- >>>> To unsubscribe from this list: send the line "unsubscribe kvm" in >>>> the body of a message to majordomo@xxxxxxxxxxxxxxx >>>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> >>> >> -- >> To unsubscribe from this list: send the line "unsubscribe kvm" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
