On 1/20/20 12:47 AM, Kim KS wrote:
In nova with setting [cinder]/ cross_az_attach option to false, nova creates instance and volume in same AZ.
but some of usecase (in my case), we need to attach new volume in different AZ to the instance.
so I need two options.
one is for nova block device mapping and attaching volume and another is for attaching volume in specified AZ.
[cinder] cross_az_attach = False enable_az_attach_list = AZ1,AZ2how do you all think of it?
As Brin mentioned there are already config hacks in Cinder to workaround cross_az_attach issues between nova and cinder. cross_az_attach in nova is config-driven API behavior which is something to avoid if possible since it's not discoverable by the end user, so piling on more config complexity is something I'd try to avoid if possible. That option wasn't even very usable until recently [1].
Can you explain your use case a bit more? It sounds like you're trying to provide essentially default zones for nova/cinder if the server and volume are not created in a specific zone? Sort of similar to how the default_schedule_zone option in nova works if a server is created without a specific zone.
[1] https://github.com/openstack/nova/commit/07a24dcef7ce6767b4b5bab0c8d3166cbe5...
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Thanks,
Matt Riedemann