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openstack undercloud

asked 2019-01-23 02:23:20 -0500

lelunicu gravatar image

hi, i seen that every compute controller ceph instance within undercloud is launched from the same image-overcloud-full.How can be launched those different instances from the same image?

openstack server list +--------------------------------------+-------------------------+--------+-------------------------+----------------+ | ID | Name | Status | Networks | Image Name | +--------------------------------------+-------------------------+--------+-------------------------+----------------+ | 349c6113-9958-44ff-8e0c-58699f34f7da | overcloud-compute-2 | ACTIVE | ctlplane= | overcloud-full | | b0a32653-6c11-4cd6-849f-05e44bdcfd19 | overcloud-controller-2 | ACTIVE | ctlplane= | overcloud-full | | 96e085d7-0e76-4b1f-a3e1-0a598f793b12 | overcloud-compute-3 | ACTIVE | ctlplane= | overcloud-full | | 887ca413-17d5-4e2a-9e4e-74a54b968551 | overcloud-controller-1 | ACTIVE | ctlplane= | overcloud-full | | 3a577b30-9c10-4c37-b15f-d6f9cdb24376 | overcloud-controller-0 | ACTIVE | ctlplane= | overcloud-full

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answered 2019-01-23 04:49:58 -0500

How not?

It is quite common to launch different instances from the same image. In a cloud, you may have ten or twenty images, but thousands of different instances. How do you think those instances were created? From those ten to twenty images, of course!

In the physical world, you install several very different servers from the same DVD. What is so special about it?

You probably wonder how it is possible that some instances are Ceph servers, others are cloud controllers and so on. This is done by configuring the instances after they have been created. In the case of Red Hat OSP, or TripleO, instances are configured automatically using Heat templates.

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so from the same image let`s say we launch 9 images-that are identical.then we configure 2 of them as compute 2 of them as ceph so on.yes? or at the moment we launch an instance from an image -we lauch it with different parameters->based on those parameters we obtain compute or ceph or so on.yes?

lelunicu gravatar imagelelunicu ( 2019-01-23 09:46:07 -0500 )edit

The answer to both questions is yes. You configure instances using launch time parameters. High-level description: Deploymentparagraph on

Bernd Bausch gravatar imageBernd Bausch ( 2019-01-23 11:58:21 -0500 )edit

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Asked: 2019-01-23 02:23:20 -0500

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Last updated: Jan 23 '19