To monitor a host-swapping activity in vSphere Web Client, view the Performance screen. A few useful counters are Swapped, Swap In, and Swap Out. These counters represent total swapping of a virtual machine on the host.

To see the swapping activity of a single VM in action, perform the following steps:

1. Open vSphere Web Client.
2. Log in to your vCenter Server.
3. On your Home screen, select Hosts and Clusters.
4. Choose memory-hungry VM.
5. Go to the Monitor tab, then the Performance tab and click on Advanced.
6. Switch the view to Memory.
7. Click on Chart Options.
8. Select the three counters: Swapped, Swap in Rate in KBps, and Swap Out Rate in KBps.
9. Click on OK. Now you should see something similar to the following image if there are swapping activities on your VM:

In the preceding example, you can see that this VM swapped out 82108 KB, and its Swap Out rate was 682 KBps and Swap In was 30 KBps.

Now to see the overall swapped activity for all VMs on a single ESXi Server, perform the following steps:

1. Open vSphere Web Client.
2. Log in to your vCenter Server.
3. On your Home screen, select Hosts and Clusters.
4. Choose the poorly performing ESXi host.
5. Go to the Monitor tab, then the Performance tab, and then click on Advanced.
6. Change the view to Memory.
7. Click on Chart Options.
8. Select the three counters: Active, Swap in Rate in KBps, and Swap Out Rate in KBps.
9. Click on OK. Now you should see something similar to the following image if there are swapping activities on your ESXi host:

In this example, you can see that this ESXi host's Swap In rate was 178 KBps and its Swap Out rate was 7428 KBps.