Unable to apply DRS settings and the available CPU resources in the parent resource pool are insufficient

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

• The host reports this alert in the Summary tab:
  
  Unable to apply DRS settings on host. The available CPU resources in the parent resource pool are insufficient for the operation.
   
• In ESXi, /var/log/hostd.log file, you see entries similar to:
  
  YYYY-MM-DDTHH:MM:SS.MSZ [58597B90 info 'TaskManager' opID=HB-host-47@98-33a6b6f7-4f] Task Created : haTask-ha-root-pool-vim.ResourcePool.updateChildResourceConfiguration-321049836
YYYY-MM-DDTHH:MM:SS.MSZ [58597B90 info 'vm:/vmfs/volumes/########-####-########b5da/example.com/example-domain.com.vmx' opID=HB-host-47@98-33a6b6f7-4f] State Transition (VM_STATE_ON -> VM_STATE_RECONFIGURING)YYYY-MM-DDTHH:MM:SS.MSZ [58597B90 warning 'HostsvcPlugin' opID=HB-host-47@98-33a6b6f7-4f] CPU/Memory resource update failed: Sysinfo error on operation returned status : Admission check failed for cpu resource. Please see the VMkernel log for detailed error informationYYYY-MM-DDTHH:MM:SS.MSZ [58597B90 info 'vm:/vmfs/volumes/########-####-########b5da/example.com/example.com.vmx' opID=HB-host-47@98-33a6b6f7-4f] RsrcMgr failed to update resource config: vim.fault.InsufficientCpuResourcesFault
YYYY-MM-DDTHH:MM:SS.MSZ [58340B90 info 'Hbrsvc'] Replicator: powerstate change VM: 3 Old: 1 New: 1
YYYY-MM-DDTHH:MM:SS.MSZ [58340B90 verbose 'Hbrsvc'] Replicator: Remove group no matching entry for VM (id=3)
YYYY-MM-DDTHH:MM:SS.MSZ [58340B90 verbose 'vim.PerformanceManager'] Adding vm 3 to poweredOnVms list
YYYY-MM-DDTHH:MM:SS.MSZ [58597B90 info 'Vmomi' opID=HB-host-47@98-33a6b6f7-4f] Throw vim.fault.InsufficientCpuResourcesFault
YYYY-MM-DDTHH:MM:SS.MSZ [58597B90 info 'Vmomi' opID=HB-host-47@98-33a6b6f7-4f] Result:
--> (vim.fault.InsufficientCpuResourcesFault) {
--> dynamicType = <unset>,
--> faultCause = (vmodl.MethodFault) null,
--> faultMessage = (vmodl.LocalizableMessage) [
--> (vmodl.LocalizableMessage) {
--> dynamicType = <unset>,
--> key = "vob.sched.group.cpu.admitfailed",
--> arg = (vmodl.KeyAnyValue) [
--> (vmodl.KeyAnyValue) {
--> dynamicType = <unset>,
--> key = "1",
--> value = "vm.4972",
--> },
--> (vmodl.KeyAnyValue) {
--> dynamicType = <unset>,
--> key = "2",
--> value = "4096",
--> },
--> (vmodl.KeyAnyValue) {
--> dynamicType = <unset>,
--> key = "3",
--> value = "mhz",
--> }
--> ],
--> message = "Group vm.4972: Can't admit VM: CPU admission check failed. Invalid reservation 4096 mhz
--> ",
--> }
--> ],
--> unreserved = -1,
--> requested = -1,
--> msg = ""

Environment

• ESXi 7.x
• ESXi 8.x
• ESX 9.x
• vCenter 7.x
• vCenter 8.x
• vCenter 9.x

Cause

This alert is displayed when the virtual machine's CPU or memory reservation is set, but the Esxi host does not have sufficient resources to allocate the reserved resource.

Resolution

To resolve this issue, either reduce the CPU/memory reservation or remove the reservation.

To remove or reduce the reservation:

1. Locate the virtual machine causing this issue from the log file.
2. In the vSphere Client, right-click the virtual machine and click Edit Settings.
3. Click the Resources tab.
4. Reduce the reserved CPU/memory value or set it to 0 to remove the reservation.
5. Click OK.

The virtual machine reconfigures and you should no longer see the alert in the Summary tab.