What is the status/roadmap of V2V (Migrating from VMware to XCPng/XO) ?
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Hello, I open this post to gather some information about the current status of the V2V process and the warm migration that goes with it.
As many in the industry, we are currently exploring our options to migrate to an alternative to vSphere/ESXi. The V2V option offered by XO is great for that but there are some limitations to it especially if you are following the latest esxi releases.
I have found the following information browsing though the forums:
The following comment from Danp (25 may 2024):
While the developers are continuously improving this feature, I don't know if warm VM migration will eventually be supported for VMFS 6.
https://xcp-ng.org/forum/post/77898The following comment from florent (2 may 2024):
[...] you can migrate without a NFS datastore, but on esxi 6.5+ , you'll need to shutdown the VM before starting the migration [...]
https://xcp-ng.org/forum/post/76709I have briefly tested to migrate a VM from vcenter/esxi 8. I tested multiple combinations of VMFS5 and VMFS6 (same shared iSCSI datastore) and connecting on vcenter or the esxi host directly. Every test resulted in a cold migration.
So the questions are, what is the currently supported configuration ? What is the roadmap for the V2V feature and its import sources ?
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Hi,
Let me try to recap: you are wondering about when or if we'll have warm migration on recent ESXi versions, right?
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@olivierlambert Essentialy yes, though it would be great to have a recap of the current situation.
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This would require an investigation because since all recent VMFS versions, we cannot access the snapshot data anymore. It could be helpful to check if there's other solutions able to do warm migration with VMware since the API approach seems a dead end due to this change
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@olivierlambert Thanks for the feedback.
Is the limitation only due to VMFS or both the esxi version and VMFS ? Because vsphere8 still supports VMFS5 and we could imagine a 2-step migration by manually moving VMs on a temporary datastore. However, if the issue is the API change with vsphere8 then I understand that it would be difficult indeed.
I'm sure the dev team has already explored the subject to build V2V in the first place but just in case it could help, here are the relevant veeam and vmware docs for vmdks transport modes (V2V is NBD mode if i'm not mistaken):
https://helpcenter.veeam.com/docs/backup/vsphere/transport_modes.html?ver=120
https://docs.vmware.com/en/VMware-vSphere/8.0/vsphere-vddk-programming-guide/GUID-15395099-5300-4D3F-BCC3-E50DCDC954C2.htmlI imagine building a viable alternative is quite a big project in itself.
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Food for thoughts @florent
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@afk the newer VMFS put more lock on the files, locking the full chain of snapshot and base disks instead of locking only the active disk.
Even VMFS5 sometimes lock the full chain.
The more open storage is a NFS, that can additionally be accessed directly by XO, not going through the soap api , giving anice performance boost and not hammering the esxi too much ( only for the metadata )We don't intend to migrate the VM running in vmware from XO automatically. A user could script it though, by using a combination of the vmware apis and xo-cli.
We never succeed in getting the disks though NBD, but it should be possible ( https://github.com/vexxhost/migratekit/blob/main/internal/vmware_nbdkit/vmware_nbdkit.go#L91 ) and ( https://vdc-download.vmware.com/vmwb-repository/dcr-public/8ed923df-bad4-49b3-b677-45bca5326e85/d2d90bb6-d1b3-4266-8ce5-443680187a9a/vim.vm.device.VirtualDevice.BackingInfo.html )
What we are mostly missing here, is internal knowledge on the Vmware side : how to get the NBD server address,how to authenticate and how to get the exportname of a disk through the soap API .Since we already have the knowledge of using NBD to read massive volume of data as long as we can connect.
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Thanks for the details @florent
@florent said in What is the status/roadmap of V2V (Migrating from VMware to XCPng/XO) ?:
the newer VMFS put more lock on the files, locking the full chain of snapshot and base disks instead of locking only the active disk.
Even VMFS5 sometimes lock the full chain.That explains why I had locking issues trying to restart the source VM on vmware after a migration test.
I'll see if I can find anything on how to use NBD with vmware.
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Thanks @afk ! Your knowledge on the "other side" might be very helpful for us!
