Virtual Machine under KVM to OpenStack

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We have some virtual machines hosted by KVM with RedHat 6.3 and we plan to install OpenStack for better manage. We want the OpenStack be able to manage those existing virtual machines. Do we need to do any migration after the OpenStack installed for those virtual machines to be able under the OpenStack?

Thanks,

Joseph

Responses

Hi Joseph,

Although KVM can be used as part of RHEL and is is the primary hypervisor for RHEL-OSP, OpenStack manages its instances in a very specific way, and it is unlikely that your existing use of KVM aligns with what OpenStack expects. And, even if it did (but, it won't), it likely wouldn't be supported.

You can refer to a couple articles on the support portal to get some ideas ([1], [2] and [3] below) on how to export a virtual machine and import it to glance, but you may also want to open a case get formal direction.

Finally, you probably won't want to install OpenStack on an existing RHEL server that has other workloads. In this case, a instance migration would be required either way.

Good luck,

John

[1] https://access.redhat.com/articles/1351473
[2] https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html-single/V2V_Guide/
[3] https://access.redhat.com/articles/1247463

John,

Thanks. The all three links you provided looked to convert from other hypervisors to KVM but my all virtual machines were already under KVM. If it requires migration from KVM to OpenStack, is there any documents, tips to do so?

Thanks,

Joseph

Ignore my last comment. Thanks.

Okay, so you said to ignore your last comment, but your question triggered some more thoughts -- hope you don't mind ;-)

Yeah, I didn't find any specific KVM to KVM instructions, although the first document specifies KVM as a supported hypervisor along with other products. Is this just implying that KVM is the supported target hypervisor, or if it is also a valid source hypervisor? Good question.

Quite honestly, you can pick up the KVM qcow2 volume file and directly import it into glance as an image. You'd also have to take care of things that normally come "standard" as part of the RHEL cloud image that may not already be part of your existing instance, such as installing cloud-init, dealing with mac addresses, and enabling the correct console device (ttyS0). (Side note, I'm not sure if virt-v2v deals with these things... haven't checked). After importing to glance, you could create a new instance from that image. Whether this approach is formally supported, you'd have to ask.

Finally, the OpenStack community documentation has a pretty good document [4] on how to create cloud-ready images manually. It has worked well for me in the past, but your mileage may vary.

John

[4] http://docs.openstack.org/image-guide/content/index.html

John,

Thanks for the info and your thoughts. It helps. I was been told by someone we need to rebuild all our virtual machines (run under KVM RedHat) when we move to OpenStack, there is no way to migration, only VMs under VMWave can be migrated to OpenStack. From the documents of the links you provided, looks there is a way to migrate for KVM to OpenStack.

Have you done the VM migration from KVM to OpenStack?

Best,

Joseph

One of my customers asked the same question about how to migration the VM mgmt by KVM to OpenStack. We w'll try to do PoC to test this Scenario. Continuously focusing on this topic.

@Feng Yuan Zhang Any news regarding this issue? We have more than 60 machines running on KVM and we now moving to openstack. We need to find an efficient and easy way to move the machines either through images, snapshot backup whatever can be helpful.