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Overview

Live migration transfers a running instance from one hypervisor node to another without instance downtime. This enables host maintenance, workload rebalancing, and fault recovery. The instance remains accessible to users throughout the migration — memory pages and disk state are transferred iteratively while the instance continues running.
Administrator Access Required — This operation requires the admin role. Contact your Xloud administrator if you do not have sufficient permissions.
Live Migration Prerequisites
  • Shared storage (Xloud Distributed Storage) must be configured, or block migration must be enabled
  • Both source and destination compute nodes must be up and enabled
  • Both nodes must run compatible hypervisor software versions
  • CPU models on source and destination must be compatible — configure a common CPU baseline in your compute configuration to prevent failures across nodes with different physical processor generations
  • For instances with a virtual TPM, Xloud Key Management must be enabled for automatic secret transfer during migration

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Migration Types

TypeShared Storage RequiredDowntimeBest For
Live MigrationYesNoneStandard workload movement with Xloud Distributed Storage-backed volumes
Block MigrationNoNoneInstances on local ephemeral disk; disk content is copied to destination during migration
Cold MigrationNoYes (instance paused)Offline resize or host draining when live migration is not possible
Migrating instances with locally-attached ephemeral disks between hosts with different CPU microarchitectures may fail. Configure cpu_mode = custom with a common CPU baseline model in your compute configuration to ensure cross-node compatibility. Contact Xloud support or configure this through XDeploy under Compute → Advanced Settings → CPU Compatibility.

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Migrate an Instance

Locate the instance

Log in to the Xloud Dashboard (https://connect.<your-domain>) and navigate to Admin → Compute → Instances. Use the project filter to locate the target instance.

Initiate live migration

In the Actions column, click Migrate Instance.Select the migration options in the dialog:
OptionDescription
Auto-select destinationThe scheduler selects the best available host
Specify destination hostManually target a specific compute node
Block migrationEnable for instances on local (non-shared) storage
Click Migrate Instance to begin.

Monitor migration progress

The instance status changes to MIGRATING. Refresh the instance list to monitor progress. A successful migration returns the instance to ACTIVE status on the destination host.
Verify the Host field in the instance detail shows the destination node name.

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Post-Migration Verification

After a live migration completes, verify the instance is operating correctly on the destination host.
Confirm instance is ACTIVE on destination
openstack server show <instance-id> \
  -f value -c status -c OS-EXT-SRV-ATTR:host
Verify migration completed (not failed)
openstack server migration list --server <instance-id>
Expected migration status: completed
Check instance console for application health
openstack console log show <instance-id> --lines 50
Instance status is ACTIVE, host shows the destination node, and migration status shows completed. Application logs show normal operation.

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Troubleshooting Migration Failures

ErrorLikely CauseResolution
guest CPU doesn't match specificationCPU microarchitecture mismatch between hostsConfigure a common CPU baseline model via XDeploy under Compute → Advanced Settings → CPU Compatibility
No valid host foundDestination lacks capacity or does not meet flavor requirementsCheck destination host capacity with openstack hypervisor show <host>
Connection timeoutNetwork disruption on the migration networkVerify connectivity between compute nodes; check firewall rules on the management interface
Block migration disk copy failedInsufficient free disk on destinationCheck available disk with openstack hypervisor show <host>

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Next Steps

Compute Hosts

Disable hosts before maintenance and drain them using live migration.

Troubleshooting

Resolve live migration failures and other common Compute issues.

Admin Guide

Return to the Compute Administration Guide index.