Devstack/LiveMigration

here are the steps to enable live-migration in Devstack :

1. follow this guide to activate a share NFS and configure libvirt properly :

http://docs.openstack.org/trunk/openstack-compute/admin/content/configuring-live-migrations.html

2. Change write permissions on the NAS so that the shared directory can be writable for everyone

3. mount NAS:/NOVA-INST-DIR/instances into /opt/stack/data/instances

4. add this line to your localrc :

NOVA_INSTANCES_PATH=/opt/stack/data/instances

don't leave the default path which is "/opt/stack/data/nova/instances" since devstack script delete the "/opt/stack/data/nova" directory.

5. start every compute node. Devstack also delete every file in NOVA_INSTANCES_PATH, so if you start one node after a first node has already booted some vm, it won't work.

compute node has to be accessable with its host name, so that libvirt could operate the migration. you can add it in /etc/hosts if needed.

you can now live-migrate vm as describe here :

http://docs.openstack.org/trunk/openstack-compute/admin/content/live-migration-usage.html