What is OpenStack live migration?

Live-migrating an instance means moving its virtual machine to a different OpenStack Compute server while the instance continues running.

What type of instances can be live migrated?

Live migration keeps your instances running during: Regular infrastructure maintenance and upgrades. Network and power grid maintenance in the data centers. Failed hardware such as memory, CPU, network interface cards, disks, power, and so on.

How do I move a VM from one host to another in OpenStack?

When you want to move an instance from one compute host to another, you can use the openstack server migrate command. The scheduler chooses the destination compute host based on its settings. This process does not assume that the instance has shared storage available on the target host.

What is block migration in OpenStack?

Block live migration, or simply block migration. The instance has ephemeral disks that are not shared between the source and destination hosts. Block migration is incompatible with read-only devices such as CD-ROMs and Configuration Drive (config_drive). Volume-backed live migration.

What is VM evacuation?

evacuate: The process of migrating one or all virtual machine (VM) instances from one host to another, compatible with both shared storage live migration and block migration.

What do you mean by live migration?

Live migration is a Hyper-V feature in Windows Server. It allows you to transparently move running Virtual Machines from one Hyper-V host to another without perceived downtime. The primary benefit of live migration is flexibility; running Virtual Machines are not tied to a single host machine.

How is live migration done?

Live migration is usually performed when a physical host machine (computer or server) needs maintenance or an update, or when a VM must be switched to a different host. The process transfers the VM memory, network connectivity and storage. Most of the migration occurs while the OS continues to run.

Why do we need live migration?

How do I enable live migration?

Use Hyper-V Manager to set up the source and destination computers for live migration

1. Open Hyper-V Manager.
2. In the navigation pane, select one of the servers.
3. In the Action pane, click Hyper-V Settings >>Live Migrations.
4. In the Live Migrations pane, check Enable incoming and outgoing live migrations.

What is a requirement for live migration?

Requirements for live migration using shared storage: All files that comprise a virtual machine (for example, virtual hard disks, snapshots, and configuration) are stored on an SMB share. Permissions on the SMB share have been configured to grant access to the computer accounts of all servers running Hyper-V.

How does live migration work?

Live migration takes place between two Hyper-V hosts. Essentially, the VM memory is copied between Hyper-V hosts. After the memory is copied, the VM on the new host can access its virtual hard disk (VHD) files and continue to run. Both hosts access shared storage where the VM’s VHD files are stored.

What Authentication Protocol does live migration use by default?

The authentication protocol Microsoft lets you choose between Kerberos and CredSSP — the default choice, but less secure of the two. It has the distinct disadvantage of requiring administrators to log directly onto the Hyper-V host to initiate a live migration.

What does it mean to live migrate an OpenStack instance?

Live-migrating an instance means moving its virtual machine to a different OpenStack Compute server while the instance continues running. Before starting a live-migration, review the chapter Configure live migrations. It covers the configuration settings required to enable live-migration,…

How do I enable auto-convergence in libvirt?

Auto-convergence is a Libvirt feature. Libvirt detects that the migration is unlikely to complete and slows down its CPU until the memory copy process is faster than the instance’s memory writes. To enable auto-convergence, set live_migration_permit_auto_converge=true in nova.conf and restart nova-compute.

How do I block-migrate an OpenStack instance to Nova?

To block-migrate instances, add the command-line option -block-migrate to the nova live-migration command, and –block-migration to the openstack server migrate command. Obtain the ID of the instance you want to migrate:

How do I configure libvirt to communicate with a compute host?

Configure the firewalls to allow libvirt to communicate between compute hosts. By default, libvirt uses the TCP port range from 49152 to 49261 for copying memory and disk contents. Compute hosts must accept connections in this range. For information about ports used by libvirt, see the libvirt documentation.