Symptoms:
Unable to apply DRS settings on host. The available CPU resources in the parent resource pool are insufficient for the operation.
hostd.log
file, you see entries similar to:2013-02-05T03:39:02.327Z [58597B90 info 'TaskManager' opID=HB-host-47@98-33a6b6f7-4f] Task Created : haTask-ha-root-pool-vim.ResourcePool.updateChildResourceConfiguration-321049836
2013-02-05T03:39:02.328Z [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)
2013-02-05T03:39:02.328Z [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 information
2013-02-05T03:39:02.328Z [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
2013-02-05T03:39:02.330Z [58340B90 info 'Hbrsvc'] Replicator: powerstate change VM: 3 Old: 1 New: 1
2013-02-05T03:39:02.330Z [58340B90 verbose 'Hbrsvc'] Replicator: Remove group no matching entry for VM (id=3)
2013-02-05T03:39:02.330Z [58340B90 verbose 'vim.PerformanceManager'] Adding vm 3 to poweredOnVms list
2013-02-05T03:39:02.330Z [58597B90 info 'Vmomi' opID=HB-host-47@98-33a6b6f7-4f] Throw vim.fault.InsufficientCpuResourcesFault
2013-02-05T03:39:02.332Z [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 = ""
0
to remove the reservation.