6.0.1

Table 1‑115. Networking Performance Enhancement Advice
# Resolution
1 Verify that VMware Tools is installed on each virtual machine.
2 If possible, use vmxnet3 NIC drivers, which are available with VMware Tools. They are optimized for high
performance.
3 If virtual machines running on the same host communicate with each other, connect them to the same vSwitch to
avoid transferring packets over the physical network.
4 Assign each physical NIC to a port group and a vSwitch.
5 Use separate physical NICs to handle the different traffic streams, such as network packets generated by virtual
machines, iSCSI protocols, vMotion tasks.
6 Ensure that the physical NIC capacity is large enough to handle the network traffic on that vSwitch. If the capacity
is not enough, consider using a high-bandwidth physical NIC (10Gbps) or moving some virtual machines to a
vSwitch with a lighter load or to a new vSwitch.
7 If packets are being dropped at the vSwitch port, increase the virtual network driver ring buffers where applicable.
8 Verify that the reported speed and duplex settings for the physical NIC match the hardware expectations and that
the hardware is configured to run at its maximum capability. For example, verify that NICs with 1Gbps are not
reset to 100Mbps because they are connected to an older switch.
9 Verify that all NICs are running in full duplex mode. Hardware connectivity problems might result in a NIC
resetting itself to a lower speed or half duplex mode.
10 Use vNICs that are TCP Segmentation Offload (TSO)-capable, and verify that TSO-Jumbo Frames are enabled
where possible.
Network Rate (Mbps)
The Network Rate chart displays network usage for virtual machines.
This chart is located in the Home view of the Virtual Machine Performance tab. It appears only at collection
levels 3 and 4.
Table 1‑116. Data Counters
Chart Label Description
Data Receive Rate Rate at which data is received across each virtual NIC instance on the virtual
machine.
n
Counter: received
n
Stats Type: Rate
n
Unit: Megabits per second (Mbps)
n
Rollup Type: Average
n
Collection Level: 2 (4)
Data Transmit Rate Rate at which data is transmitted across each virtual NIC instance on the virtual
machine.
n
Counter: transmitted
n
Stats Type: Rate
n
Unit: Megabits per second (Mbps)
n
Rollup Type: Average
n
Collection Level: 2 (4)
Chart Analysis
Network performance depends on application workload and network configuration. Dropped network
packets indicate a bottleneck in the network. To determine whether packets are being dropped, use esxtop
or the advanced performance charts to examine the droppedTx and droppedRx network counter values.
vSphere Monitoring and Performance
82 VMware, Inc.