6.0.1

Table 1‑20. Networking Performance Enhancement Advice (Continued)
# Resolution
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.
Datacenters
The data center charts contain information about CPU, disk, memory, and storage usage for data centers.
The help topic for each chart contains information about the data counters displayed in that chart. The
counters available are determined by the collection level set for vCenter Server.
CPU (MHz)
The CPU (MHz) chart displays CPU usage for the 10 clusters in the data center with the most CPU usage.
This chart is located in the Clusters view of the Datacenters Performance tab.
Table 1‑21. Data Counters
Chart Label Description
<cluster> Amount of CPU currently in use by the cluster. The active CPU usage is approximately equal to the
ratio of the used CPU cycles to the available CPU cycles.
The maximum possible value is the frequency of the processors multiplied by the number of cores.
For example, a two-way SMP virtual machine using 4000MHz on a host that has four 2GHz
processors is using 50% of the CPU (4000 ÷ 4 × 2000) = 0.5).
n
Counter: usagemhz
n
Stats Type: Rate
n
Unit: MegaHertz (MHz)
n
Rollup Type: Average (Minimum/Maximum)
n
Collection Level: 1 (4)
Chart Analysis
A short spike in CPU usage indicates that you are making the best use of cluster resources. However, if the
value is constantly high, the CPU demanded is likely greater than the CPU capacity available. A high CPU
usage value can lead to increased ready time and processor queuing of the virtual machines on the hosts in
the cluster.
If performance is impacted, consider taking the following actions.
vSphere Monitoring and Performance
24 VMware, Inc.