Cinder

Setup on compute node with no cinder storage

Asked by Christoph L

I have a OpenStack Havana setup with 2 Server. For the installation I was following this guide: http://docs.openstack.org/havana/install-guide/install/yum/content/

Everything runs smoothly. Now I want to add an additional Compute Node, but without providing disk space for Cinder volumes.
How can I install Cinder on the second compute node without providing disk space, but be able to launch instances and get the volumes from the first compute node?

- Controller
- Compute Node with Cinder
- (Compute node without Cinder)

Greetings
Chris

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lirenke (lvhancy) said : 		#1

What is your back-end storage type? LVM?
Well, for Lvm, I think you can deploy cinder-volume in server A, and deploy nova-compute in both servers.
If you really have to deploy cinder-volume in another server, just do not make LVM volume group.So, the cinder-volume will not become the disk provider.
Can it solve your question?

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Christoph L (schlafenistluxus) said : 		#2

Hello
the storage back-end is LVM. I followed this tutorial: http://docs.openstack.org/havana/install-guide/install/yum/content/

So I installed another compute node without any cinder packages/configuration. At the dashboard I can create Volumes but not attach them to the instances running on the new compute node. The "Attaching" process is just quitting without any error message in the Dashboard. Attaching the Volumes on instances running on the cinder node works perfect.

Which packages I have to install on an compute node to get Volumes attached on the running instances with the LVM storage back-end?

Greetings
Chris

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lirenke (lvhancy) said : 		#3

Hi, I don't use dashboard so I don't understand what is "Attaching" process you said.
Cinder use iSCSI to export the volume and attath them to an instance. You use tgt or iet in the cinder node? tgt is default.(see the "iscsi_helper" in cinder.conf)
It seems the volumes created in cinder node can export successfully, because you can attach them to the instance launching in the same node.
So I think you can check these commands like "iscsi_discovery ", "iscsiadm" exist and useful in the new compute node.If not, install the iscsi-initiator or open-isci.
Otherwise, I recommend you check the nova's log in the new compute node and find the reason.

Can you help with this problem?

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