Yellow Bricks

by Duncan Epping

What is new for vMotion in vSphere 6.0?

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vMotion is probably my favourite VMware feature ever. It is one of those features which revolutionized the world and just when you think they can’t really innovate anymore they take it to a whole new level. So what is new?

  • Cross vSwitch vMotion
  • Cross vCenter vMotion
  • Long Distance vMotion
  • vMotion Network improvements
    • No requirement for L2 adjacency any longer!
  • vMotion support for Microsoft Clusters using physical RDMs

That is a nice long list indeed. Lets discuss each of these new features one by one and lets start at the top with Cross vSwitch vMotion. Cross vSwitch vMotion basically allows you to do what the name tells you. It allows you to migrate virtual machines between different vSwitches. Not just from vSS to vSS but also from vSS to vDS and vDS to vDS. Note that vDS to vSS is not supported. This is because when migrating from vDS metadata of the VM is transferred as well and the vSwitch does not have this logic and cannot handle the metadata. Note that the IP Address of the VM that you are migrating will not magically change, so you will need to make sure both  the source and the destination portgroup belong to the same layer 2 network. All of this is very useful during for instance Datacenter Migrations or when you are moving VMs between clusters for instance or are migrating to a new vCenter instance even.

Next on the list is Cross vCenter vMotion. This is something that came up fairly frequent when talking about vMotion, will we ever have the ability to move a VM to a new vCenter Server instance? Well as of vSphere 6.0 this is indeed possible. Not only can you move between vCenter Servers but you can do this with all the different migration types there are: change compute / storage / network. You can even do it without having a shared datastore between the source and destination vCenter aka “shared nothing migration. This functionality will come in handy when you are migrating to a different vCenter instance or even when you are migrating workloads to a different location. Note, it is a requirement for the source and destination vCenter Server to belong to the same SSO domain. What I love about this feature is that when the VM is migrated things like alarms, events, HA and DRS settings are all migrated with it. So if you have affinity rules or changed the host isolation response or set a limit or reservation it will follow the VM!

My personal favourite is Long Distance vMotion. When I say long distance, I do mean long distance. Remember that the max tolerated latency was 10ms for vMotion? With this new feature that just went up to 150ms. Long distance vMotion uses socket buffer resizing techniques to ensure that migrations succeed when latency is high. Note that this will work with any storage system, both VMFS and NFS based solutions are fully supported. (** was announced with 100ms, but updated to 150ms! **)

Then there are the network enhancements. First and foremost, vMotion traffic is now fully supported over an L3 connection. So no longer is there the need for L2 adjacency for your vMotion network, I know a lot of you have asked for this and I am happy to be able to announce it. On top of that. You can now also specify which VMkernel interface should be used for migration of cold data. It is not something many people are aware off, but depending on the type of migration you are doing and the type of VM you are migrating it could be in previous versions that the Management Network was used to transfer data. (Frank Denneman described this scenario in this post.) For this specific scenario it is now possible to define a VMkernel interface for “Provisioning traffic” as shown in the screenshot below. This interface will be used for, and let me quote the documentation here, “Supports the traffic for virtual machine cold migration, cloning, and snapshot creation. You can use the provisioning TPC/IP stack to handle NFC (network file copy) traffic during long-distance vMotion. NFC provides a file-type aware FTP service for vSphere, ESXi uses NFC for copying and moving data between datastores.”

Full support for vMotion of Microsoft Cluster virtual machines is also newly introduced in vSphere 6.0. Note that these VMs will need to use physical RDMs and only supported with Windows 2008, 2008 R2, 2012 and 2012 R2. Very useful if you ask me when you need to do maintenance or you have resource contention of some kind.

That was it for now… There is some more stuff coming with regards to vMotion but I cannot disclose that yet unfortunately.

Reader Interactions

Comments

  1. What about different CPU architectures? Cross vCenter vMotion sounds awesome, but if you’re migrating from a Nehelem architecture to a Haswell architecture, it won’t help much unless you can get away with that. And yes, I know about EVC, but at some point, ya gotta change CPU feature set.

    • Cross cpu architecture vMotion can be done if you tweak vmx settings, but experience shows that your vMotioned VMs has a tendency to crash (BSOD) a bit quicker than before. Especially when vMotioning from AMD to Intel.

  2. “Full support for vMotion of Microsoft Cluster virtual machines”, seriously? This would be awesome.

  3. How does shared storage come in to play with Long Distance vMotion? Is that going to be a limiting factor, any of the storage companies working on anything?

  5. I agree with you that vMotion is together with FT one of my favourite technologies ever.

    When talking about cross vCenter vMotion, what are going to be the constraints when new vCenter releases come out? same vCenter build? same vCenter minor/major version?

      • Both the source and destination need to be ESXi/vCenter 6.0+. They need to be part of the same SSO domain to use the web client to perform the task. If they are part of different SSO domain, you can use the API to perform the vMotion.

  7. This might be a dumb question, but I’ll ask it! vMotion support for MSCS, storage vMotion shouldn’t matter since the nodes should be using shared disk correct? Could you still do a storage vMotion potentially to move system volumes only?

  8. How does security change with the additional vMotion capability? Historically this traffic was never encrypted but this wasn’t too much of an issue over an L2 network. If the traffic is going over an L3 network I’d hope there would be some degree of encryption introduced.

  9. Duncan, what happens to performance graph data/event lists/task lists of guests migrated between vCenter servers? Are there appropriate fields/values present to allow external tools (be them third party or even things like vROPS) to recognise this sort of migration and not consider the migrated virtual machine “new”?

    • ” things like alarms, events, HA and DRS settings are all migrated with it” >> afaik performance details are not migrated with the VM

      I have not heard anything about potential vR Ops integration with this feature

  10. Hi Duncan,

    How will Long Distance vMotion work with asynchronous replication technology (either vSphere Replication or Storage array)?

    Without support for this it is not a viable Disaster Avoidance technology as I assume today you need to move the entire VM’s storage every time you perform a vMotion.

    I remember EMC talking about using VVOLs and asynchronous replication (i.e. VPLEX Geo) that would essentially on a VM by VM basis perform a delta storage replication before vMotioning.

    Is this something that we are likely to see in 6.x or is it down to the storage array vendors to sort this out?

    I also see that the following feature has been added:

    Replication-Assisted vMotion – Enables customers, with active-active replication set up between two sites, to perform a more efficient vMotion resulting in huge time and resource savings – as much as 95 percent more efficient depending on the size of the data.

    Can you elaborate on this feature more and confirm if it is related to what I am talking about above?

    Many thanks
    Mark

  11. So does that mean that today the only way to perform Long Distance vMotion is do a combined vMotion and Storage vMotion?

    Are there plans to integrate Long Distance vMotion with vSphere Replication so you only need to move the delta with Storage vMotion?

  12. Are there any plans for a stateful vMotion? Example being – I have a customer that vMotion’s their SQL server from one host to another, and part of their application tier has a persistent connection to the SQL instance that will die requiring a service restart should the connection as much as blip… I would think if the state could be transitioned as part of the vMotion process that could be alleviated. Thoughts?

  14. Stupid question time… But if vMotion traffic is supported over L3 does this mean the provisioning traffic for NFC is as well?

  16. If we have 2 essential plus license are we able to perform cross vmotion vcenter?

  18. Hi Duncan

    Does DRS use cross vswitch vMotion or is it just a manual migration?

    Imran

  19. Hi Guyz,

    I looking for an information…i’m supposed to use the Cross vCenter VMotion in the next month but before that i have to migrate one Domain SSO. (i’ve 2 vcenter with their own SSO for each site)

    My question is, how to do that? how to migrate one Domain SSO into an other Vmware SSO Server ?

  20. Hi Guyz,

    Any idea that VMware vSphere 5.5/6.0 Essential kit plus supports storage vMotion feature.

    Much appreciate your advise

    Thanks in Advance

    Regards,
    Vignesh

  21. What are the potential challenges related to cross vcentre VM migrations as well as long distance VM migration yet to be addressed?

  22. Hi Duncan,

    While performing the cross vCenter vmotion’s, How do we replicate/restore configuration’s, policies, features on destination vDS which were created on Source vDS ? do we have any document for the workflow and usecases on this ?

    Thanks,
    Santhosh S