6.0.1

Table 1‑18. Memory Performance Enhancement Advice (Continued)
# Resolution
5 If the cluster is a DRS cluster:
n
Increase the number of hosts, and migrate one or more virtual machines to the new host.
n
Check the aggressiveness threshold. If the value is low, increase the threshold. This might help avoid hot spots
in the cluster.
6 Add more physical memory to one or more hosts.
Network (Mbps)
The Network (Mbps) chart displays network speed for the 10 hosts in the cluster with the most network
usage.
This chart is located in the Hosts view of the Cluster Performance tab.
Table 1‑19. Data Counters
Chart Label Description
<host> Average rate at which data is transmitted and received across all NIC instances on the host.
n
Counter: usage
n
Stats Type: Rate
n
Unit: Megabits per second (Mbps)
n
Rollup Type: Average (Minimum/Maximum)
n
Collection Level: 1 (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.
If packets are being dropped, adjust the virtual machine shares. If packets are not being dropped, check the
size of the network packets and the data receive and transfer rates. In general, the larger the network
packets, the faster the network speed. When the packet size is large, fewer packets are transferred, which
reduces the amount of CPU required to process the data. When network packets are small, more packets are
transferred but the network speed is slower because more CPU is required to process the data.
NOTE In some instances, large packets might result in high network latency. To check network latency, use
the VMware AppSpeed performance monitoring application or a third-party application.
If packets are not being dropped and the data receive rate is slow, the host is probably lacking the CPU
resources required to handle the load. Check the number of virtual machines assigned to each physical NIC.
If necessary, perform load balancing by moving virtual machines to different vSwitches or by adding more
NICs to the host. You can also move virtual machines to another host or increase the host CPU or virtual
machine CPU.
If you experience network-related performance problems, also consider taking the actions listed below.
Table 1‑20. 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.
Chapter 1 Monitoring Inventory Objects with Performance Charts
VMware, Inc. 23