Clearer default implmentation for dhcp_options...

'pass' is less clear than 'return None' for the base implementation.

Change-Id: Iff53d5eb7e88e18849696d858b3d910b6ea71e63
Hard reboot doesn't re-create instance folder

When use share storage like ceph, instance's disk data is in ceph,
instance's disk doesn't rely on local instance folder anymore. So
when rebooting a instance, we should create the instance folder if
it is missed.

Closes-Bug: #1349978

Change-Id: I5948c7979a7dbe7764fba6cad1d9867893824024
Correct columns covered in migrations_instance_uuid_and_status_idx

Migration 142 added a new index migrations_instance_uuid_and_status_idx
that covers columns deleted, instance_uuid and status, but the index
added to the model only covers instance_uuid and status.

Change-Id: I6ffdeabbab54223b2be844048917588adaceb9bb
Partially-implements: blueprint validate-migrations-and-model
Add missing indexes from 203 migration to model

Migration 203 added two new indexes to existing tables, but did not
update the model to include them.

Change-Id: If63e8f6c34bb7e4e43cbbda82346e2caffc8eeff
Partially-implements: blueprint validate-migrations-and-model
VMware: optimize resource pool usage

There is no need to query the backend for the cluster resource pool.
This is known at init. Using this save a backend query with a VM
spawn.

Change-Id: I336f8e4a2b68f694ce4a88f7fab76214efb17a0c
Merge "Clearer default implmentation for dhcp_options..."
Merge "Correct columns covered in migrations_instance_uuid_and_status_idx"
Merge "Add missing indexes from 203 migration to model"
Merge "Hard reboot doesn't re-create instance folder"
Merge "VMware: optimize resource pool usage"