6.5.1

Table 1‑114. Memory Performance Enhancement Advice
# Resolution
1 Verify that VMware Tools is installed on each virtual machine. The balloon driver is installed with VMware Tools
and is critical to performance.
2 Verify that the balloon driver is enabled. The VMkernel regularly reclaims unused virtual machine memory by
ballooning and swapping. Generally, this does not impact virtual machine performance.
3 Reduce the memory space on the virtual machine, and correct the cache size if it is too large. This frees up memory
for other virtual machines.
4 If the memory reservation of the virtual machine is set to a value much higher than its active memory, decrease the
reservation seing so that the VMkernel can reclaim the idle memory for other virtual machines on the host.
5 Migrate one or more virtual machines to a host in a DRS cluster.
6 Add physical memory to the host.
Network (Mbps)
The Network (Mbps) chart displays network bandwidth for the virtual machine.
This chart is located in the Home view of the Virtual Machine Performance tab.
Table 1‑115. Virtual Machine Counters
Chart Label Description
Usage Average rate at which data is transmied and received across all virtual NIC
instances connected to the virtual machine.
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 the application workload and network conguration. Dropped network
packets indicate a boleneck 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.
N In some instances, large packets might result in a high network latency. To check the 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 dierent 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 following actions.
vSphere Monitoring and Performance
80 VMware, Inc.