Hi all,

  I order to reach maximum performance on my centos kvm hosts I have use these params:

  - On /etc/grub.conf:

    kernel /vmlinuz-2.6.18-164.11.1.el5 ro root=LABEL=/ elevator=deadline quiet

  - On sysctl.conf

   # Special network params
   net.core.rmem_default = 8388608
   net.core.wmem_default = 8388608
   net.core.rmem_max = 16777216
   net.core.wmem_max = 16777216
   net.ipv4.tcp_rmem = 1048576 4194304 16777216
   net.ipv4.tcp_wmem = 1048576 4194304 16777216

   # Disable netfilter on bridges.
   net.bridge.bridge-nf-call-ip6tables = 0
   net.bridge.bridge-nf-call-iptables = 0
   net.bridge.bridge-nf-call-arptables = 0

   # Virtual machines special kernel params
   vm.swappiness = 0