[Nova Scheduler] Option any availability zone (AZ)

[Dat Le]

In many cases, first time, admin only uses default_availability_zone as unique AZ. That means any functions create new VM lead that VM boot on default zone: "nova" (all current host).
After that, admin ungroups their hosts into some separate AZs. However, many before functions did not specified any AZs such as auto healing, heat template. So, after deviding into many AZs, creating new VM lead that VM can boot on the zone different from default zone "nova". It is not convenient!
Solution for this situation is modify all old functions to add specified AZ.
To avoid above situation, I think if not specify AZ in creating new instance, nova scheduler should choice default_availability_zone instead of any zone.

[Matt Riedemann (mriedem)]

I'm not sure I understand the issue.

https://docs.openstack.org/nova/latest/configuration/config.html#DEFAULT.default_availability_zone

is the default AZ for a compute service. If the server is created without specifying an availability zone, it can be scheduled to any host and migrated to any other host across AZs.

The only time the server is restricted to a certain AZ is:

1. The user requested a specific AZ when creating the server (and the user should not request "nova", see the warning here: https://docs.openstack.org/nova/latest/user/aggregates.html#availability-zones-azs).

2. The default_schedule_zone https://docs.openstack.org/nova/latest/configuration/config.html#DEFAULT.default_schedule_zone option is set.

It sounds like what you want is #2 so that VMs which are created without a specific AZ being requested will go into a default AZ. If so, then configure that option in nova-api.

[Matt Riedemann (mriedem)]

I've marked this as incomplete. If I haven't answered your question/issue in comment 1, please set this back to New status and provide a series of steps explaining the issue to recreate the bug.

[Launchpad Janitor (janitor)]

[Expired for OpenStack Compute (nova) because there has been no activity for 60 days.]