> For the complete documentation index, see [llms.txt](https://developer.harness.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.harness.io/resilience-testing/chaos-engineering/faults/chaos-fault-categories/vmware/vcenter/vmware-vm-poweroff.md).

# VMware VM power off (by MOID)

VMware VM power off (by MOID) is a VMware chaos fault that powers off the VMs whose Managed Object IDs are listed in `APP_VM_MOIDS` for `TOTAL_CHAOS_DURATION` seconds, then powers them back on. The fault talks to vCenter directly (no VMware Tools required on the guest) and supports running targets in `parallel` or `serial` (`SEQUENCE`).

Use this fault to test how a workload behaves when a VMware VM disappears: whether replicas absorb the load, whether DNS/load-balancer health checks remove the VM cleanly, whether monitoring detects the outage within the alerting SLA, and whether on-call alerts fire correctly.

{% hint style="info" %}
**RUN YOUR FIRST EXPERIMENT**

If you have not configured the chaos infrastructure yet, go to [Quickstart](/resilience-testing/chaos-engineering/new-to-chaos-engineering/quickstart.md) to install the chaos infrastructure and run an experiment end to end.
{% endhint %}

***

### Use cases <a href="#use-cases" id="use-cases"></a>

* **VM disappearance:** When a VM is powered off, do replicas absorb the load inside the SLO budget?
* **Health-check fidelity:** Does the load balancer detect the unhealthy VM inside the failover SLA?
* **Stateful workloads:** Does a clustered stateful workload (database, message broker) recover correctly when one node disappears?

***

### Prerequisites <a href="#prerequisites" id="prerequisites"></a>

* **Kubernetes version:** 1.21 or later for the chaos infrastructure cluster.
* **vCenter reachable:** The chaos infrastructure can reach the vCenter server over port 443.
* **VM MOIDs known:** You know the MOID of each VM you want to power off (visible via vCenter Managed Object Browser, `govc`, or PowerCLI).
* **vCenter chaos role:** The vCenter user (`VCENTER_USERNAME`) is mapped to the chaos role described in [VMware permissions](/resilience-testing/chaos-engineering/faults/chaos-fault-categories/vmware/permissions.md), including Virtual Machine → Interaction → Power Off and Power On.

***

### Supported environments <a href="#supported-environments" id="supported-environments"></a>

| Platform                                | Support status                                                               |
| --------------------------------------- | ---------------------------------------------------------------------------- |
| Linux VMs hosted on vSphere / vCenter   | Supported                                                                    |
| Windows VMs hosted on vSphere / vCenter | Supported (this fault is OS-agnostic since it acts on the VM, not the guest) |
| Standalone ESXi (no vCenter)            | Not supported                                                                |

***

### Permissions required <a href="#permissions-required" id="permissions-required"></a>

This fault is classified as **Basic**. Map `VCENTER_USERNAME` to the chaos role described in [VMware permissions](/resilience-testing/chaos-engineering/faults/chaos-fault-categories/vmware/permissions.md). The role needs at minimum:

* Virtual machine → Interaction → Power Off
* Virtual machine → Interaction → Power On

***

### Authentication <a href="#authentication" id="authentication"></a>

| Tunable            | Description                            |
| ------------------ | -------------------------------------- |
| `VCENTER_SERVER`   | vCenter server URL or hostname.        |
| `VCENTER_USERNAME` | vCenter user mapped to the chaos role. |
| `VCENTER_PASSWORD` | Password for `VCENTER_USERNAME`.       |

Store each credential as a text secret in [Harness Secret Manager](/harness-ai/use-harness-platform/secrets/add-use-text-secrets.md) and reference the secret identifier when configuring the experiment.

***

### Fault tunables <a href="#fault-tunables" id="fault-tunables"></a>

**Required parameters**

| Tunable        | Description                                                            | Default    |
| -------------- | ---------------------------------------------------------------------- | ---------- |
| `APP_VM_MOIDS` | Comma-separated list of VM Managed Object IDs (for example `vm-1234`). | (required) |

**Chaos parameters**

| Tunable                | Description                                                                                                                                                                                                      | Default    |
| ---------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------- |
| `TOTAL_CHAOS_DURATION` | Total duration of the fault in seconds. The VMs stay powered off for this period.                                                                                                                                | `60`       |
| `CHAOS_INTERVAL`       | Delay in seconds between iterations when running for more than one cycle.                                                                                                                                        | `30`       |
| `SEQUENCE`             | `parallel` (power off all listed VMs at once) or `serial` (power off one VM at a time).                                                                                                                          | `parallel` |
| `RAMP_TIME`            | Wait period in seconds before and after the fault. Go to [ramp time](/resilience-testing/chaos-engineering/faults/chaos-fault-categories/common-tunables-for-all-faults.md#ramp-time) to read how it is applied. | `0`        |

**vCenter authentication**

| Tunable            | Description                            | Default |
| ------------------ | -------------------------------------- | ------- |
| `VCENTER_SERVER`   | vCenter server URL or hostname.        | `""`    |
| `VCENTER_USERNAME` | vCenter user mapped to the chaos role. | `""`    |
| `VCENTER_PASSWORD` | Password for `VCENTER_USERNAME`.       | `""`    |

Tunables that apply to every fault are documented in [common tunables for all faults](/resilience-testing/chaos-engineering/faults/chaos-fault-categories/common-tunables-for-all-faults.md).

***

### Fault execution in brief <a href="#fault-execution-in-brief" id="fault-execution-in-brief"></a>

Authenticates to vCenter (`VCENTER_SERVER`), powers off each VM in `APP_VM_MOIDS` (in `parallel` or `serial` per `SEQUENCE`), waits `TOTAL_CHAOS_DURATION` seconds, then powers them back on.

***

### Expected behavior during fault execution <a href="#expected-behavior-during-fault-execution" id="expected-behavior-during-fault-execution"></a>

* Each VM in `APP_VM_MOIDS` transitions to `poweredOff` state.
* Workloads on those VMs become unreachable; replicas (if any) absorb the load.
* After the duration ends, each VM is powered back on and the guest OS boots up.

{% hint style="info" %}
**WHEN THE FAULT ENDS**

The chaos pod calls `PowerOnVM_Task` for each VM in `APP_VM_MOIDS`. Guest OS boot time depends on the workload and is not included in `TOTAL_CHAOS_DURATION`.
{% endhint %}

#### Signals to watch <a href="#signals-to-watch" id="signals-to-watch"></a>

* **VM power state:** Use a [command probe](/resilience-testing/chaos-testing/probes/command-probe.md) running `govc vm.info <vm-name>` and assert the state.
* **Workload health:** Use an [HTTP probe](/resilience-testing/chaos-engineering/use-chaos-engineering/probes/http-probe.md) on a user-visible endpoint served by other replicas (not the targeted VMs).

***

### Verify the fault execution effect <a href="#verify-the-fault-execution-effect" id="verify-the-fault-execution-effect"></a>

1. **Inspect VM power state in vCenter.**

   In vCenter UI, find each VM by MOID. The state should be `Powered Off` during the chaos window and `Powered On` afterwards.
2. **Confirm guest OS recovery.**

   After the fault ends, SSH (or RDP) into each VM to confirm the OS booted and the workload restarted.

***

### Recovery and cleanup <a href="#recovery-and-cleanup" id="recovery-and-cleanup"></a>

* **End of duration:** The chaos pod powers each VM back on.
* **Abort:** Stopping the experiment from Chaos Studio also triggers `PowerOnVM_Task`.
* **Manual recovery:** If a VM remains powered off, power it on from vCenter UI or via `govc vm.power -on <vm>`.

***

### Limitations <a href="#limitations" id="limitations"></a>

* **MOID required:** The fault accepts only MOIDs, not VM names. To target by name, use [VMware VM power off (by name)](/resilience-testing/chaos-engineering/faults/chaos-fault-categories/vmware/vcenter/vmware-vm-poweroff-by-name.md).
* **Boot time not counted:** Guest OS boot time after power-on is not included in the duration.
* **Hard power off:** This is a hardware-level power off, not a graceful guest shutdown. Workloads must tolerate sudden disappearance.

***

### Troubleshooting <a href="#troubleshooting" id="troubleshooting"></a>

<details>

<summary>VMware VM power off fails with managed object not found in Harness Chaos Engineering</summary>

The MOID in APP\_VM\_MOIDS may be incorrect or the VM may have been removed. Confirm the MOID via vCenter MOB at https\:///mob or with govc vm.info -dump .

</details>

<details>

<summary>VMware VM power off fails with permission denied</summary>

VCENTER\_USERNAME needs Virtual machine > Interaction > Power Off and Power On on the target VMs. Verify the role assignment in vCenter Permissions and retry.

</details>

***

### Related faults <a href="#related-faults" id="related-faults"></a>

* [VMware VM power off (by name)](/resilience-testing/chaos-engineering/faults/chaos-fault-categories/vmware/vcenter/vmware-vm-poweroff-by-name.md): Power off VMs by name (via ESXi host enumeration) instead of by MOID.
* [VMware process kill](/resilience-testing/chaos-engineering/faults/chaos-fault-categories/vmware/linux/vmware-process-kill.md): Kill a process inside the VM instead of powering off the entire VM.
* [VMware service stop](/resilience-testing/chaos-engineering/faults/chaos-fault-categories/vmware/linux/vmware-service-stop.md): Stop a service inside the VM instead of powering off the entire VM.