79 lines
2.2 KiB
ReStructuredText
79 lines
2.2 KiB
ReStructuredText
===============================================
|
|
Migrate single instance to another compute host
|
|
===============================================
|
|
|
|
When you want to move an instance from one compute host to another,
|
|
you can use the :command:`nova 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.
|
|
|
|
#. To list the VMs you want to migrate, run:
|
|
|
|
.. code-block:: console
|
|
|
|
$ nova list
|
|
|
|
#. After selecting a VM from the list, run this command where :guilabel:`VM_ID`
|
|
is set to the ID in the list returned in the previous step:
|
|
|
|
.. code-block:: console
|
|
|
|
$ nova show VM_ID
|
|
|
|
#. Now, use the :command:`nova migrate` command.
|
|
|
|
.. code-block:: console
|
|
|
|
$ nova migrate VM_ID
|
|
|
|
#. To migrate an instance and watch the status, use this example script:
|
|
|
|
.. code-block:: bash
|
|
|
|
#!/bin/bash
|
|
|
|
# Provide usage
|
|
usage() {
|
|
echo "Usage: $0 VM_ID"
|
|
exit 1
|
|
}
|
|
|
|
[[ $# -eq 0 ]] && usage
|
|
|
|
# Migrate the VM to an alternate hypervisor
|
|
echo -n "Migrating instance to alternate host"
|
|
VM_ID=$1
|
|
nova migrate $VM_ID
|
|
VM_OUTPUT=`nova show $VM_ID`
|
|
VM_STATUS=`echo "$VM_OUTPUT" | grep status | awk '{print $4}'`
|
|
while [[ "$VM_STATUS" != "VERIFY_RESIZE" ]]; do
|
|
echo -n "."
|
|
sleep 2
|
|
VM_OUTPUT=`nova show $VM_ID`
|
|
VM_STATUS=`echo "$VM_OUTPUT" | grep status | awk '{print $4}'`
|
|
done
|
|
nova resize-confirm $VM_ID
|
|
echo " instance migrated and resized."
|
|
echo;
|
|
|
|
# Show the details for the VM
|
|
echo "Updated instance details:"
|
|
nova show $VM_ID
|
|
|
|
# Pause to allow users to examine VM details
|
|
read -p "Pausing, press <enter> to exit."
|
|
|
|
.. note::
|
|
|
|
If you see this error, it means you are either
|
|
trying the command with the wrong credentials,
|
|
such as a non-admin user, or the ``policy.json``
|
|
file prevents migration for your user:
|
|
|
|
``ERROR (Forbidden): Policy doesn't allow compute_extension:admin_actions:migrate
|
|
to be performed. (HTTP 403)``
|
|
|
|
The instance is booted from a new host, but preserves its configuration
|
|
including its ID, name, any metadata, IP address, and other properties.
|