Information Technology Reference
In-Depth Information
Perform the following steps to create a real-time chart for a host's CPU usage:
1.
Launch the vSphere Web Client if it is not already running, and connect to a vCenter
Server instance.
2.
Navigate to the Hosts And Clusters or VMs And Templates view.
3.
In the Navigator, select a host. This shows you the Summary tab.
4.
Click the Performance tab, and switch to Advanced view.
5.
Click the Chart Options link.
6.
In the Chart Options dialog box, select the CPU resource type and the Real-Time display
interval.
7.
Set Chart Type to Stacked Graph (Per VM).
8.
Select all objects.
You should see a separate object for each VM hosted on the selected ESXi host.
9.
Select the CPU Usage (Average) performance counter.
10.
Click OK to apply the chart settings and return to the Performance tab.
This chart shows the usage of all the VMs on the selected ESXi host in a stacked fashion.
From this view, you should be able to determine whether there is a specii c VM or group of VMs
consuming abnormal amounts of CPU capacity.
VMkernel Balancing Act
Always remember that on an oversubscribed ESXi host, the VMkernel will load balance the VMs
based on current loads, reservations, and shares represented on individual VMs and/or resource
pools.
In this scenario, we identii ed the application within the VM as CPU bound, so these two
performance charts should clearly identify why the VM isn't performing well. In all likelihood,
the ESXi host on which the VM is running doesn't have enough CPU capacity to satisfy the
requests of all the VMs. Your solution, in this case, would be to use the resource allocation tools
described in Chapter 11, “Managing Resource Allocation,” to ensure that this specii c applica-
tion receives the resources it needs to perform at acceptable levels.
Monitoring Memory Usage
Monitoring memory usage, whether on a host or a VM, can be challenging. The monitoring itself
is not difi cult; it's the availability of the physical resource that can be a challenge. Of the four
resources, memory can be oversubscribed without much effort. Depending on the physical form
