openstack-manuals/doc/admin-guide/source/cli-cinder-scheduling.rst

Manage Block Storage scheduling

As an administrative user, you have some control over which volume back end your volumes reside on. You can specify affinity or anti-affinity between two volumes. Affinity between volumes means that they are stored on the same back end, whereas anti-affinity means that they are stored on different back ends.

For information on how to set up multiple back ends for Cinder, refer to multi_backend.

Example Usages

1. Create a new volume on the same back end as Volume_A:

   $ openstack volume create --hint same_host=Volume_A-UUID \
     --size SIZE VOLUME_NAME

2. Create a new volume on a different back end than Volume_A:

   $ openstack volume create --hint different_host=Volume_A-UUID \
     --size SIZE VOLUME_NAME

3. Create a new volume on the same back end as Volume_A and Volume_B:

   $ openstack volume create --hint same_host=Volume_A-UUID \
     --hint same_host=Volume_B-UUID --size SIZE VOLUME_NAME

   Or:

   $ openstack volume create --hint same_host="[Volume_A-UUID, \
     Volume_B-UUID]" --size SIZE VOLUME_NAME

4. Create a new volume on a different back end than both Volume_A and Volume_B:

   $ openstack volume create --hint different_host=Volume_A-UUID \
     --hint different_host=Volume_B-UUID --size SIZE VOLUME_NAME

   Or:

   $ openstack volume create --hint different_host="[Volume_A-UUID, \
     Volume_B-UUID]" --size SIZE VOLUME_NAME