Manually increasing the heap memory of components in vCenter Server 7.x and 8.x

Products

• VMware vCenter Server

Issue/Introduction

• Performance issues in components such as the Inventory Service and vSphere web-client.

Environment

• VMware vCenter Server 7.x.
• VMware vCenter Server 8.x.

Cause

Heap memory of vCenter components gets exhausted.

Resolution

This article provides steps to increase the heap memory of individual vCenter Server components to resolve performance issues in components such as the vSphere Web Client/vSphere Client.

Note: Service names may vary between vCenter Server versions 7.x and 8.x. As such, see Stopping, Starting or Restarting VMware vCenter Server Appliance 6.x & above services (2109887) below for service names and how to stop and start services in vCenter Server Appliance and Windows Center Server.

Important: Updates of vCenter server may revert these changes, so document accordingly and as needed to repeat this process.

vCenter Server Appliance:

1. Use SSH to connect to the VCSA as root and enter the Bash shell by typing shell and pressing Enter
2. Run the following command to output memory assigned to each of the services:
   cloudvm-ram-size -l

3. Increase the amount of memory assigned to the services by running the following command, using the vCenter HTML5 web client (or "vsphere-ui"), as an example:

cloudvm-ram-size -C #### vsphere-ui

Note: #### should be replaced with the desired amount of memory in MB.
For example, this command would increase the memory of the vsphere-ui service from 768 MB to 2048 MB.

cloudvm-ram-size -C 2048 vsphere-ui

There is no "one size fits all" memory value to set in this scenario, however - as a guide, double the size of currently assigned memory of the service that has an issue. This may need to be repeated.

4. Restart the service that has been altered, in this example - vsphere-ui:

service-control --stop vsphere-ui;service-control --start vsphere-ui;

5. Confirm that the service has now been allocated the increased memory by using this command:
   
   cloudvm-ram-size -l