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detaching root device volume of an instance

asked 2014-11-19 07:19:13 -0600

swapnil gravatar image

In Openstack juno version, I created cinder volume(which is bootable) from an OS image, and created instance out of it. I want to temporarily detach that root device volume(os disk) of an instance. But I am getting following error

ERROR (Forbidden): Can't detach root device volume (HTTP 403) (Request-ID: req-57159c1c-5835-4a44-8e41-1b822b92127e)

Even if instance's power state is "Shutdown", then detach root volume attempted still get the same error. Earlier in Openstack havana this same task to detach root volume was working but now in juno facing the above issue.

Looks like this is a by design implementation of openstack. Can someone please confirm this ? Is there any possibility of achieving this in latest version(Juno) of openstack with some tweak ?

Would appreciate any suggestion/comments on this.



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I am just wondering if you could detach root volume of instance in shutdown state, how would you be able to start instance either in Havana was possible attaching volumes to not running instances

dbaxps gravatar imagedbaxps ( 2014-11-19 08:36:03 -0600 )edit

3 answers

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answered 2016-03-04 03:02:06 -0600

Enno Gröper gravatar image

Yes. This is intentionally by design. Seems like there were some problems, when detaching boot volume of an instance (even in Shutdown state) was possible.

Seems like this is addressed here:

When this gets merged, it will be possible to detach boot volumes of shelved instances. Currently it looks like this could be merged in the N release (it's too late for mitaka).

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answered 2016-03-04 04:54:18 -0600

capsali gravatar image

It is possible but with a lot of tweaking and not something you want to do on daily basis.

Here is a tutorial : post #10

Bassically you shutdown the instance, set the mountpoint of the volume to /dev/vdb in mysql and then you can detach with nova volume-detach <instanceId> <volumeId>.

Hope the spec above will be implemented and you can do this from cli client.

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answered 2014-11-27 03:43:01 -0600

I am also facing same issue in juno

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Asked: 2014-11-19 07:15:39 -0600

Seen: 8,578 times

Last updated: Mar 04 '16