VMware ESXi and vSphere Cluster Management
How to Acknowledge Triggered Alarms in VMware vSphere
Learn how to acknowledge triggered vSphere alarms, verify acknowledgment details, and distinguish acknowledgment from Reset to Green.
In vSphere, an alarm is a rule-based monitoring mechanism. It evaluates conditions on an inventory object, such as a virtual machine, ESXi host, cluster, datastore, or datacenter. When a configured condition is met, the alarm becomes triggered and can invoke alarm actions such as notifications, tasks, scripts, or escalation behavior.
Acknowledging a triggered alarm is an administrative action that records that an operator has reviewed the alert and taken ownership of it. Acknowledgment does not repair the underlying problem and does not necessarily return the alarm to its Normal state.
What Alarm Acknowledgment Does
When an operator acknowledges an alarm, vCenter Server records the action against the triggered alarm entry. This gives the operations team visibility into who reviewed the alert and when.
- It indicates that the alert has been reviewed or is being actively handled.
- It identifies the vCenter user who performed the action.
- It records the acknowledgment date and time.
- It suppresses further configured alarm actions for the current triggered condition.
- It does not resolve the monitored condition.
- It does not automatically change the alarm state to Normal.
For example, if a datastore capacity warning has fired, an administrator can acknowledge it after beginning capacity remediation. The acknowledgment shows that the alert has an owner, while the alarm can remain triggered until datastore utilization falls below the configured threshold.
Where to Find Triggered Alarms
vCenter Server is the central management platform for vSphere inventory, alarms, events, and administrative actions. The vSphere Client is the management interface used to inspect and operate on those alarms.
- Sign in to the vSphere Client.
- Select the relevant inventory object in vCenter Server. This can be a datacenter, cluster, ESXi host, virtual machine, datastore, or another monitored object.
- Open the object's Monitor tab.
- Open Issues.
- Select Triggered Alarms.
The list is scoped to the object you selected. Its contents depend on alarms associated with that object and alarms inherited from applicable parent objects. If an expected alarm is missing, check both related parent and child objects, as well as your permissions.
How to Acknowledge a Triggered Alarm
- Open the Triggered Alarms view for the appropriate inventory object.
- Identify the alarm that requires acknowledgment. Check the object, alarm name, severity, and current condition before acting.
- Right-click the alarm entry to open its context menu.
- Select Acknowledge.
- Refresh or review the alarm list and inspect its acknowledgment-related fields.
The exact layout can vary between vSphere Client versions, but the operation follows the same principle: select the triggered alarm, open its context menu, and choose Acknowledge.
How to Verify the Acknowledgment
After the operation completes, use the alarm entry to confirm that the correct alarm was acknowledged. The primary confirmation fields are Acknowledged and Acknowledged By.
| Field | What it confirms | Expected value after acknowledgment |
|---|---|---|
| Acknowledged | Whether an operator has acknowledged the triggered alarm | Enabled, selected, or otherwise shown as acknowledged, with an acknowledgment time |
| Acknowledged By | The vCenter user who performed the action | The identity of the operator's vCenter account |
| Alarm state | Whether the monitored condition is still active | It may remain Warning or Alert; acknowledgment does not require Normal state |
| Triggered Alarms presence | Whether the active alarm entry is still displayed | Usually still present while the condition remains triggered |
The acknowledgment timestamp and user identity provide useful audit information during shift handoffs, incident reviews, and operational reporting.
Acknowledging Versus Resolving an Alarm
A triggered alarm is an alarm whose configured condition is currently met. For example, a host connectivity condition may remain active while a host is intentionally offline for maintenance.
Acknowledgment does not repair that condition. If the condition remains active, the alarm can remain in the Triggered Alarms list and retain a Warning or Alert state. The alarm normally returns to Normal only after its configured condition clears and the alarm is evaluated again.
In the maintenance example, the responsible operator can acknowledge the host connectivity alarm after confirming the planned work. That records ownership and suppresses further configured actions for the current condition, but it does not prove that host connectivity has been restored.
Reset to Green Behavior
Reset to Green is a separate manual operation. It forces the alarm state back to Normal and can remove the alarm from the Triggered Alarms list even when the actual monitored condition still exists.
| Action | Primary purpose | Effect on configured alarm actions | Effect on alarm state | Effect on Triggered Alarms view | Underlying condition required to be resolved? | Operational risk |
|---|---|---|---|---|---|---|
| Acknowledge | Record that an operator reviewed and owns the alert | Suppresses further configured actions for the current triggered condition | Can remain Warning or Alert | Usually remains listed while the condition is active | No | Low if the team continues investigation; it can create false confidence if treated as resolution |
| Reset to Green | Manually clear the alarm state | Clears the active alarm state and may prevent continued visibility of the current entry | Returns to Normal by administrative action | Can remove the entry even while the condition remains active | No, but resolution should normally be confirmed first | High if it masks an unresolved issue or delays remediation |
Use Reset to Green carefully. It may be appropriate for a confirmed false positive, or after an administrator has reviewed a condition and intentionally decided to clear the state. If the underlying condition is still present, the alarm may trigger again when monitoring evaluates the rule.
Operational Decision Guidance
When to acknowledge
- The alert has been reviewed.
- A responsible operator or team owns the investigation.
- Repeated notifications or other configured actions are no longer needed during the current investigation.
- The team understands that the alarm may remain triggered until the condition clears.
When to leave the alarm active
- The alert has not yet been reviewed.
- The team still needs automated notifications, escalation, or other configured alarm actions.
- No owner has accepted responsibility for the condition.
- The alert is being used as an active signal for an ongoing incident.
When to reset to green
- The monitored condition is confirmed resolved and the state has not yet cleared naturally.
- The alarm is confirmed to be a false positive and the administrator wants to clear the active entry.
- An administrator has deliberately reviewed the consequences of manually clearing the alarm.
Document the underlying issue, remediation status, and reason for any manual reset. This prevents a cleared alarm from being mistaken for a technically resolved incident.
Common Examples
Datastore capacity warning
A datastore usage alarm fires after utilization crosses its threshold. The administrator investigates, begins removing unnecessary data or extending capacity, and acknowledges the alarm. The alarm remains triggered until utilization no longer meets the rule, unless the administrator intentionally uses Reset to Green.
Host connectivity alarm during maintenance
An ESXi host is intentionally unavailable during planned work. After confirming the maintenance activity, the responsible operator acknowledges the connectivity alarm. The acknowledgment records ownership but does not indicate that connectivity has returned. The alarm reaches Normal naturally only after the configured condition clears.
Known false positive
An administrator reviews a triggered alarm and determines that it is non-actionable or incorrectly triggered. The administrator may use Reset to Green to clear the active entry, while recognizing that the underlying condition could still exist and cause the alarm to trigger again.
Troubleshooting Acknowledgment Problems
The alarm remains in Triggered Alarms after acknowledgment
The monitored condition is probably still active. Acknowledgment does not clear the condition or automatically restore Normal state. Investigate and correct the condition, wait for the alarm rule to evaluate as normal, or use Reset to Green only with deliberate administrative justification.
The alarm was reset to green but the problem continues
Reset to Green cleared the displayed alarm state rather than resolving the operational issue. Continue technical remediation, validate the relevant metric or event, and confirm that the condition does not retrigger.
The expected alarm cannot be found
The selected inventory object may have the wrong scope, the alarm may apply to a related object, or permissions may limit visibility. Check appropriate parent and child objects, confirm where the alarm is configured or triggered, and verify that the account has the required vCenter privileges.
The acknowledgment user or time is missing
Refresh the Triggered Alarms view and verify that the intended alarm entry was selected. Confirm the active vCenter session identity. If necessary, review available task or event records to determine whether the operation completed under the expected account.
Exam-Relevant Distinctions
- Acknowledge records operator review and suppresses further configured actions for the current triggered condition.
- Acknowledgment does not repair the underlying issue and does not necessarily remove the alarm from the Triggered Alarms list.
- Reset to Green is a separate manual action that returns the alarm to Normal and can hide an unresolved condition.
- The Acknowledged and Acknowledged By fields confirm acknowledgment status and operator identity.
- An alarm normally returns to Normal when its configured condition clears, not merely because an operator acknowledged it.
Summary
To acknowledge a vSphere alarm, select the relevant inventory object, open Monitor, select Issues, open Triggered Alarms, right-click the alarm, and choose Acknowledge. Verify the Acknowledged and Acknowledged By fields afterward.
Use acknowledgment to communicate review and ownership while preserving visibility of an active condition. Use Reset to Green only as an intentional administrative action, preferably after confirming remediation or documenting why the alarm is being cleared. For related operational procedures, return to the vSphere alarm acknowledgment guide.