Hi,
i'm experience poor network performance and i wonder if anyone got any ideas how to solve this problem.
When running iperf (no customization without changing running time to 60 seconds) internally on a Windows 2008 R2 VM i reach about 428 MB/s.
When running iperf (no customization without changing running time to 60 seconds) between two Windows 2008 R2 VMs in the same ESXi server i reach about 200 MB/s.
When running iperf (no customization without changing running time to 60 seconds) between two Windows 2008 R2 VMs in the same ESXi server i reach about 110 MB/s using 10 Gbps network. Looks very much like a 1 Gbps network but it is not.
A few TCP/IP settings has been tuned in the Windows VM/VMs:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\TCPIP\Parameters
o TcpTimedWaitDelay 30
o MaxUserPort 32768
o TcpMaxDataRetranmission 5
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\AFD\Parameters
o EnableDynamicBacklog 00000001
o MinimumDynamicBacklog 00000020
o MaximumDynamicBacklog 00001000
o DynamicBacklogGrowthDelta 00000010
o KeepAliveInterval 1
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\{Interface GUID}*
o TcpNoDelay 1
o TcpAckFrequency 1
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\DisableTaskOffload has been set to 0,1 and 16.
TCP global parameters looks like this:
----------------------------------------------
Receive-Side Scaling State: disabled
Chimney Offload State: automatic
NetDMA State: disabled
Direct Cache Acess (DCA): enabled
Receive Window Auto-Tuning Level: normal
Add-On Congestion Control Provider: ctcp
ECN Capability: disabled
RFC 1323 Timestamps: disabled
I'm using ESXi 5.0.0 build-702118
I have seen the below message in the VMkernel log file indicating that the network spped is not limited to 1 Gbps:
VMotionSend: 3508: 1352573741598557 S: Sent all modified pages to destination (network bandwidth ~843.801 MB/s)
vMotion using the same NICs as the VMs during the vMotion test.
Anyone?