[openstack-dev] [Nova] z/VM introducing a new config driveformat

Dan Smith dms at danplanet.com
Wed May 30 14:01:48 UTC 2018

> can I know a use case for this 'live copy metadata or ' the 'only way
> to access device tags when hot-attach?  my thought is this is one time
> thing in cloud-init side either through metatdata service or config
> drive and won't be used later? then why I need a live copy?

If I do something like this:

  nova interface-attach --tag=data-network --port-id=foo myserver

Then we update the device metadata live, which is visible immediately
via the metadata service. However, in config drive, that only gets
updated the next time the drive is generated (which may be a long time
away). For more information on device metadata, see:


Further, some of the drivers support setting the admin password securely
via metadata, which similarly requires the instance pulling updated
information out, which wouldn't be available in the config drive. For



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