On 2 Sep 2015, at 09:22, Pasi Kärkkäinen <pasik at iki.fi> wrote: > On Tue, Sep 01, 2015 at 06:47:18AM +0200, Christoph wrote: >> Hi All >> > > Hello, > >> it is possible to tune dom0/domU for better IO/network performance? >> Since I have changed to Cenots7 dom0, I have a really poor IO >> performance inside a PV VM. >> >> I have already done what is described on >> http://wiki.xenproject.org/wiki/Tuning_Xen_for_Performance >> It is better now but still significantly worse than with centos6 dom0 >> >> my settings: >> >> xen parameter: dom0_mem=1024M cpufreq=xen dom0_max_vcpus=2 >> dom0_vcpus_pin >> >> xl sched-credit >> Cpupool Pool-0: tslice=30ms ratelimit=1000us >> Name ID Weight Cap >> Domain-0 0 1024 0 >> samael 1 256 0 >> satan 2 512 0 >> amon 3 256 0 >> leviathan 4 512 0 >> >> echo 1048576 > /proc/sys/net/ipv4/tcp_limit_output_bytes on dom0 >> >> the both domU's satan and leviathan are very IO performance oriented >> (NFS server and downloading vm) >> >> Is there something more what I can do or try? >> >> could it be a selinux issue? I have it in permissive mode there, not >> disabled. But permissive means only to collect the info not enforcing >> the rules... >> >> (I use the xen45 pkgs) >> > > You forgot to mention the most important thing.. what kind of performance numbers are you seeing? What are you expecting? > > > Thanks, > > — > Pasi Here’s a useful disk i/o stress test program that I got good results with on openSUSE 13.1, by running it on several VM’s overnight: Using Bonnie++ for filesystem performance benchmarking http://archive09.linux.com/feature/139742 HTH Keith Roberts