The VMware vCenter Server UI displays a memory exhaustion alert daily at the same time. The VAMI Overall Health & Memory is in an Alert Status with the message: Appliance is running low on memory. Add more memory to the machine
VMware vCenter Server 8.x
The high memory utilization on the VMware vCenter Server is caused by a scheduled task (VMware vSphere Lifecycle Manager HCL Validation) that runs daily at the same time, leading to the memory exhaustion alerts.
Note: A complete backup of the VMware vCenter Server must be taken before any changes are made.
To resolve this issue, the validation task can either be rescheduled to a different time (Workaround) or the memory allocated to the VMware vCenter Server virtual machine can be increased.
Option 1: Reschedule the Scheduled Task (Workaround)
Reschedule the VMware vSphere Lifecycle Manager HCL Validation task to run during a less resource-intensive time of the day.
Refer: How Do You Change or Reschedule a Scheduled vSphere Task
Option 2: Increase Memory Allocation
Access the ESXi host interface where the VMware vCenter Server VM is running.
Shut down the VMware vCenter Server VM before you make any memory changes.
Right-click on the VMware vCenter Server VM and select Edit Settings.
In the Hardware tab, select Memory.
Change the memory size to the desired amount.
Click OK or Save to apply the changes.
Power on the VM to start it with the new memory allocation.