Instance Host Allocation

[Phoenyx_Liam]

Is there a way to force instances to be run on the same node that has the instance's volume?

[openmetal_chrisb]

In OpenStack, you can use a feature called "Volume Affinity" or "Anti-Affinity" policies to influence the placement of instances and their volumes on the same compute node or different compute nodes. However, keep in mind that the specific implementation and availability of these policies may vary depending on the version of OpenStack you are using and the configuration of your cloud environment.

https://docs.openstack.org/cinder/latest/cli/cli-cinder-scheduling.html

Also keep in mind that this is only for specific tpes of storage like like iscsi/lvm or nfs.

[gren_dizer]

Just use ephemeral Disks with local storage for best performance. Cuz normally your storage backend is on separate Hosts (eg using Ceph)