Difference between revisions of "GSP Virtualisation with Xen"
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xe-switch-network-backend bridge | xe-switch-network-backend bridge | ||
| + | Then, configure | ||
| + | sysctl -w net.core.rmem_max=134217728 # BDP | ||
| + | sysctl -w net.core.wmem_max=134217728 # BDP | ||
| + | sysctl -w net.ipv4.tcp_rmem="4096 87380 134217728 " # _ _ BDP | ||
| + | sysctl -w net.ipv4.tcp_wmem="4096 65536 134217728 " # _ _ BDP | ||
| + | sysctl -w net.core.netdev_max_backlog=300000 | ||
| + | |||
| + | It also helped significantly to increase the txqueuelen on the '''vif''' interface to the VM. | ||
| + | ifconfig vif3.0 txqueuelen 300000 | ||
| + | almost doubles the network throughput. Of course the txqueuelen was already set to 300000 on the physical interfaces. There is no way to make this permanent yet, so a cronjob doing | ||
| + | ifconfig | grep -P '^vif\d+\.\d+' | awk '{system("ifconfig "$1" txqueuelen 300000")}' | ||
| + | may help there. | ||
| + | |||
| + | Trond Eirik Haavarstein's blog post (see below) also had this nice script to be executed on each dom0, which got another 100Mbps: | ||
| + | |||
| + | #! /bin/sh | ||
| + | echo Setting checksum off on VIFs | ||
| + | VIFLIST=`xe vif-list | grep "uuid ( RO) " | awk '{print $5}'` | ||
| + | for VIF in $VIFLIST | ||
| + | do | ||
| + | echo Setting ethtool-tx=off and ethtool-rx=off on $VIF | ||
| + | xe vif-param-set uuid=$VIF other-config:ethtool-tx="off" | ||
| + | xe vif-param-set uuid=$VIF other-config:ethtool-rx="off" | ||
| + | done | ||
| + | echo Setting checksum off on PIFs | ||
| + | PIFLIST=`xe pif-list | grep "uuid ( RO) " | awk '{print $5}'` | ||
| + | for PIF in $PIFLIST | ||
| + | do | ||
| + | echo Setting ethtool-tx=off and ethtool-rx=off on $PIF | ||
| + | xe pif-param-set uuid=$PIF other-config:ethtool-tx="off" | ||
| + | xe pif-param-set uuid=$PIF other-config:ethtool-rx="off" | ||
| + | done | ||
Some references: | Some references: | ||
* http://wiki.xen.org/xenwiki/Network_Throughput_Guide.html | * http://wiki.xen.org/xenwiki/Network_Throughput_Guide.html | ||
| + | * http://www.xenappblog.com/2010/citrix-xenserver-slow-network-performance by Trond Eirik Haavarstein | ||
| + | * http://djlab.com/2011/05/dropped-vif-tx-packets-on-xenserver/ (on the txqueue length on vifs) | ||
== How NOT to copy your LVMs from RHEL5 == | == How NOT to copy your LVMs from RHEL5 == | ||
