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Nova migration issue NOT SSH

asked 2016-11-16 08:09:30 -0500

schegi gravatar image


i currently configure migration in nova and came across a strange issue. First, i want migration without the use of ssh but via qemu+tcp. So i configured nova.conf and libvirtd.conf accordingly. For 'live' migration it all works fine. With 'live' i mean using the clis (nova or openstack) and provide a destination host for the migration (e.g. nova live-migration <server-id> <host> or openstack server migrate --live <host> <server-id>). Doing so i could migrate every instance from everywhere to everywhere in my cloud setup.

But as soon as i try to migrate without explicitely defining a destination host (e.g nova migrate <server-id>), nova falls back to ssh based migration, which fails cause of missing keys. This also happens on server resize, if the resize is not performed locally, allow_resize_to_same_host = True is set but this does not enforce local resize just allows it. Again, i do not want to distribute ssh keys, i want 'pure' qemu+tcp, later qemu+tsl based migration. Is this even possible for destination-less migration (destination host choosen by the scheduler) and if so, how to configure this?

Btw: i am only using shared storages CEPH/ISCSI no ephemeral storage.

Thy Stefan

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answered 2016-11-16 21:37:18 -0500

Nova probably uses SSH for cold migration because there is no direct cold migration support in libvirt. There is however a Mitaka spec which addresses the problem. From this review, it would seem that the new target for implementing the spec is Ocata.

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answered 2016-11-16 21:17:31 -0500

silently gravatar image

you can ,use rsync ,migrate source machine (linux platform) to target machine (linux platform also ),

rsync source mahine all file ,from root (/)

I think it's simple and a effective way.

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Sure you can do that, but this is actually not what i wanted/asked. Due to security concerns, we do not what to allow password-less ssh connectivity between our compute nodes, but we still want openstack controlled migration, and probably resize support.

schegi gravatar imageschegi ( 2016-11-22 09:33:36 -0500 )edit

answered 2016-11-16 09:05:38 -0500

schegi gravatar image

Ok, if i am not totally wrong it seems like that 'cold' migration (this includes resize) always needs ssh accessebility between the machines configured.


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Asked: 2016-11-16 08:09:30 -0500

Seen: 308 times

Last updated: Nov 16 '16