> ## 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.

# Compute Integration

> Configure Xloud Compute for Optimization compatibility — verify shared storage, live migration capability, and host state for optimization action execution.

## Overview

The Optimization relies on Xloud Compute for both cluster state collection and
migration execution. All optimization actions that produce live migrations require
compute hosts to support live migration — which in turn requires shared storage for
instance disks. This page covers the compute requirements, verification steps, and
configuration adjustments needed before enabling optimization in production.

<Note>
  **Prerequisites**

  * Administrator privileges
  * Xloud Compute deployed and operational
  * Xloud Distributed Storage or equivalent shared storage for instance volumes
</Note>

***

## Shared Storage Requirement

<Warning>
  Live migration requires that instance disks are backed by shared storage (Xloud
  Distributed Storage or equivalent). Instances with local ephemeral disks cannot
  be live-migrated. Such instances will cause actions to fail during plan execution.
</Warning>

Verify that the instances targeted by optimization are using shared storage:

```bash title="Check instance storage backend" theme={null}
openstack server show <instance-id> \
  -f value -c "os-extended-volumes:volumes_attached"
```

Instances with no attached volumes (or with ephemeral disk only) cannot be live-migrated.
Work with project owners to migrate critical ephemeral-disk instances to volume-backed
equivalents before enabling optimization strategies that include those instances.

***

## Verify Compute Host Availability

Optimization actions only target compute hosts that are up, enabled, and not in
maintenance state.

```bash title="Check all compute services" theme={null}
openstack compute service list --service nova-compute
```

| Column     | Required Value |
| ---------- | -------------- |
| **State**  | `up`           |
| **Status** | `enabled`      |

Hosts with `state: down` or `status: disabled` are automatically excluded from
optimization targets. Disabled hosts do not receive live-migrated instances.

***

## Verify Live Migration Capability

```bash title="Check migration capability per host" theme={null}
openstack hypervisor show <hostname> \
  -f value -c hypervisor_hostname -c state -c status
```

Perform a test live migration between two hosts in the optimization segment:

```bash title="Test live migration between hosts" theme={null}
openstack server migrate <test-instance-id> \
  --live-migration \
  --host <destination-host>

openstack server show <test-instance-id> \
  -f value -c status
```

Expected: instance returns to `ACTIVE` status on the destination host.

***

## CPU Compatibility for Live Migration

Live migration between hosts with different CPU architectures or feature sets can fail.
Configure a common CPU baseline in the Compute service to ensure compatibility across
all hosts in the optimization segment.

<Tabs>
  <Tab title="XDeploy" icon="browser">
    <Steps titleSize="h3">
      <Step title="Open Advanced Configuration" icon="settings">
        Open **XDeploy** and navigate to **Advanced Configuration**. In the **Service Tree**
        (left panel), select **nova**.
      </Step>

      <Step title="Edit the Compute Configuration" icon="file-pen">
        Click **New File** or select an existing `nova.conf` from the **File Browser**
        (right panel). Add the following in the **Code Editor** (center panel):

        ```ini title="/etc/xavs/config/nova/nova.conf" theme={null}
        [libvirt]
        cpu_mode = custom
        cpu_model = Cascadelake-Server-noTSX
        ```
      </Step>

      <Step title="Save and Apply" icon="circle-check">
        Click **Save Current File**. Return to **Operations** and run **reconfigure** to
        apply the CPU compatibility settings across all compute hosts.

        <Check>CPU compatibility baseline configured and applied via XDeploy.</Check>
      </Step>
    </Steps>
  </Tab>

  <Tab title="CLI" icon="terminal">
    Edit the configuration file directly:

    ```ini title="nova.conf -- CPU compatibility" theme={null}
    [libvirt]
    cpu_mode = custom
    cpu_model = Cascadelake-Server-noTSX
    ```
  </Tab>
</Tabs>

<Tip>
  Use `cpu_mode = custom` with a CPU model that represents the lowest common denominator
  across all compute hosts in the optimization segment. This is especially important in
  clusters with heterogeneous hardware generations.
</Tip>

***

## Host Aggregates for Optimization Scope

Use host aggregates to define which hosts are eligible for optimization. Assign all
hosts intended for consolidation to a single aggregate, then scope your audits to
that aggregate:

```bash title="Create optimization aggregate" theme={null}
openstack aggregate create optimization-zone
openstack aggregate add host optimization-zone compute-01
openstack aggregate add host optimization-zone compute-02
openstack aggregate add host optimization-zone compute-03
```

***

## Validation

<Tabs>
  <Tab title="Dashboard" icon="gauge">
    Navigate to **Compute > Hypervisors** (admin view). Verify:

    * All compute hosts show `State: Up` and `Status: Enabled`
    * No hosts are in maintenance or down state

    <Check>All compute hosts are up and enabled, ready to serve as migration targets.</Check>
  </Tab>

  <Tab title="CLI" icon="terminal">
    ```bash title="Verify all hosts are available" theme={null}
    openstack compute service list \
      --service nova-compute \
      -f table -c Host -c State -c Status
    ```

    ```bash title="Check per-host utilization" theme={null}
    openstack hypervisor list --long \
      -f table -c Hostname -c "Running VMs" -c "vCPUs Used" -c "Memory MB Used"
    ```

    <Check>All hosts show `State: up`, `Status: enabled`, and capacity is visible for optimization planning.</Check>
  </Tab>
</Tabs>

***

## Next Steps

<CardGroup cols={2}>
  <Card title="Action Policies" href="/services/optimization/admin-guide/action-policies" color="#197560">
    Configure manual approval vs automatic execution for optimization plans.
  </Card>

  <Card title="Security" href="/services/optimization/admin-guide/security" color="#197560">
    Secure the service account used by the Applier to call the Compute API.
  </Card>

  <Card title="Troubleshooting" href="/services/optimization/admin-guide/troubleshooting" color="#197560">
    Diagnose live migration failures during plan execution.
  </Card>

  <Card title="Compute Admin Guide" href="/services/compute/admin-guide" color="#197560">
    Configure compute hosts, shared storage, and live migration settings.
  </Card>
</CardGroup>