> ## Documentation Index
> Fetch the complete documentation index at: https://docs.xloud.tech/llms.txt
> Use this file to discover all available pages before exploring further.

# Instance HA Admin Guide

> Configure and operate Xloud Instance HA — deploy monitors, create failover segments, register hosts, tune recovery methods, and integrate with compute clusters.

<p style={{ fontSize: '1.25rem', fontWeight: 700, marginBottom: '0.75rem' }}>Overview</p>

Xloud Instance HA provides automated detection and recovery of failed compute hosts and
instances. Administrators configure the failover infrastructure — segments, host monitors,
instance monitors, and notification drivers — that power zero-touch recovery for project
workloads. This guide covers the full administrative lifecycle, from initial deployment
to tuning recovery policies for production.

<Warning>
  All operations in this guide require administrator privileges. Changes to segment
  configuration and monitor settings affect active recovery workflows immediately.
</Warning>

<Tabs>
  <Tab title="XDeploy" icon="gauge">
    <Steps titleSize="h3">
      <Step title="Open XDeploy Configuration" icon="settings">
        Log in to **XDeploy** (`https://xdeploy.<your-domain>`) and navigate to **Configuration**.
      </Step>

      <Step title="Enable Host HA" icon="toggle-right">
        Select the **Advance Features** tab. Toggle **Enable Host HA** to **Yes**.

        This automatically enables the underlying services (`enable_masakari` and
        `enable_hacluster`) with no manual file editing required.
      </Step>

      <Step title="Save and deploy" icon="play">
        Click **Save Configuration**, then navigate to **Operations** and run a
        **deploy** or **reconfigure** action.

        <Check>Instance HA services start automatically across all registered compute hosts.</Check>
      </Step>
    </Steps>
  </Tab>

  <Tab title="CLI" icon="terminal">
    Enable Instance HA by setting the flags in the globals configuration and deploying:

    ```bash title="Create Instance HA globals override" theme={null}
    cat > /etc/xavs/globals.d/_50_instance_ha.yml << 'EOF'
    enable_masakari: "yes"
    enable_hacluster: "yes"
    EOF
    ```

    ```bash title="Deploy the Instance HA service" theme={null}
    xavs-ansible deploy -t masakari
    ```

    <Check>Instance HA API, engine, host monitor, and instance monitor containers are running on all target hosts.</Check>
  </Tab>
</Tabs>

***

<p style={{ fontSize: '1.25rem', fontWeight: 700, marginBottom: '0.75rem' }}>In This Guide</p>

<CardGroup cols={4}>
  <Card title="Architecture" icon="layers" href="/services/instance-ha/admin-guide/architecture" color="#197560">
    Component diagram, service roles, and the detection-to-recovery data flow.
  </Card>

  <Card title="Failover Segments" icon="shield-check" href="/services/instance-ha/admin-guide/failover-segments" color="#197560">
    Create and manage failover segments that define recovery scope and host groupings.
  </Card>

  <Card title="Host Monitors" icon="heart-pulse" href="/services/instance-ha/admin-guide/host-monitors" color="#197560">
    Deploy and configure host monitors for host-level failure detection.
  </Card>

  <Card title="Instance Monitors" icon="monitor" href="/services/instance-ha/admin-guide/instance-monitors" color="#197560">
    Configure instance-level monitors for guest OS and process failure detection.
  </Card>

  <Card title="Notification Drivers" icon="bell" href="/services/instance-ha/admin-guide/notification-drivers" color="#197560">
    Configure IPMI, libvirt, and custom notification drivers for failure signaling.
  </Card>

  <Card title="Recovery Methods" icon="rotate" href="/services/instance-ha/admin-guide/recovery-methods" color="#197560">
    Configure and tune recovery methods — rescheduler, reserved host, and auto-evacuate.
  </Card>

  <Card title="Engine Configuration" icon="settings" href="/services/instance-ha/admin-guide/engine-config" color="#197560">
    Configure the recovery engine — timeouts, retry limits, and notification handling.
  </Card>

  <Card title="Security" icon="lock" href="/services/instance-ha/admin-guide/security" color="#197560">
    Harden the Instance HA service account and restrict API access via RBAC.
  </Card>

  <Card title="Troubleshooting" icon="wrench" href="/services/instance-ha/admin-guide/troubleshooting" color="#197560">
    Diagnose monitor failures, recovery timeouts, and notification processing errors.
  </Card>
</CardGroup>

***

<p style={{ fontSize: '1.25rem', fontWeight: 700, marginBottom: '0.75rem' }}>Architecture Summary</p>

| Service              | Role                                                        |
| -------------------- | ----------------------------------------------------------- |
| **API**              | REST API for segment, host, and notification management     |
| **Engine**           | Processes notifications and orchestrates recovery workflows |
| **Host Monitor**     | Detects host failures via IPMI/libvirt probing              |
| **Instance Monitor** | Detects instance failures via XAVS Guest Agent probing      |

***

<p style={{ fontSize: '1.25rem', fontWeight: 700, marginBottom: '0.75rem' }}>Next Steps</p>

<CardGroup cols={4}>
  <Card title="Instance HA User Guide" icon="book-open" href="/services/instance-ha/user-guide" color="#197560">
    Enable protection on instances and monitor recovery events from an operator perspective.
  </Card>

  <Card title="Instance HA Overview" icon="layers" href="/services/instance-ha/index" color="#197560">
    Service overview and getting started with Instance HA.
  </Card>
</CardGroup>