"storage_availability_zone" in the [DEFAULT] section of
manila's configuration file has allowed deployers to configure
and manage both service (scheduler, share manager) and storage
system availability. However, quite often manila's services
(api, scheduler, share and data managers) are run on a dedicated
control plane that is a different failure domain from that of
the storage that manila manages.
Also, when using share replication, deployers would need to
run multiple manila share manager services with different
configuration files, each with their own
"storage_availability_zone".
To allow flexibility of separating service and storage
availability zones, we introduce a new configuration option
"backend_availability_zone" within the share driver/backend
section. When this option is used, it will override the value
of the "storage_availability_zone" from the [DEFAULT] section.
Change-Id: Ice99a880dd7be7af94dea86b31a6db88be3d7d9b
Implements: bp per-backend-availability-zones
a75fe3d7cc