Add support for RDM disk mappings

This issue was originally opened by @showry as hashicorp/terraform#17283. It was migrated here as a result of the provider split. The original body of the issue is below.

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As per the current terraform vsphere documentation,Terraform doesn't support RDM disk mappings. Is there any future scope that this feature gonna be supported?

[vancluever]

Hey @showry, sorry for the delay in replying on addressing this topic.

At this point, I don't think the vSphere provider is going too end up supporting RDM disks anytime soon. There are no plans to support these kinds of disks, and since their makeup under the hood is so much different from standard disks, we would need to take that into consideration when authoring support - they would probably need to be their own virtual device class (such as raw_disk), but share configuration data with standard disk sub-resources such as unit_number. We would also need to consider how we would track them, as we are now using the UUID of a disk's backing as the primary identifier for a disk device once it has been deployed.

Nothing is set in stone, of course - necessity may end up driving us to support this anyway, or we might get a pull request allowing for the support. But I don't want to leave this issue open saying "soon" disingenuously. Longer term you might want to check back to see if this has changed.

Thanks!

[surajsub]

For some of our sap installations this would be a key feature - How do i up this requirement ?

[vancluever]

@surajsub and @showry I think I may have closed this pre-maturely. I want to make sure this is tracked, even if it's a longer-term goal, so I'm re-opening the issue.

What I mentioned about our plans hasn't changed, so barring any the aforementioned factors, this won't be available for a while yet. But now at least it's available for us to track and update when work is ready.

@surajsub the 👍 implied in your message is enough to vote on this, otherwise the best way you could help speed up development of the feature is to see if anyone wanted to work on a PR 🙂

Thanks!

[pbusquemdf]

I too would like to have this feature added. We are using 3PAR remote copy to have replication of single instance application, and we can't provision those machine.

I do not mind Terraform not supporting RDM disk implicitly , if we can have an option to mark a disk to be ignored.

Right now, if we put the disk into the lifecycle-> ignore_changes we would still get the "unsupported type" error.

A workaround would be to parse the config, and if the device is an unsupported type AND marked as to be ignored, well, ignore it. If new drives are added afterward, handle those as you normally would.

That way, we can still use RDM until it is fully supported.

[scheying]

Same here. Right now we have to delete machines that have an RDM attached from the TF state. If Terraform would just ignore RDMs that would already help a lot.

[sergioagm]

We also are interested in this. We use RDM attached disks from a SAN to implement Windows Clusters. Either supporting them fully or as @pbusquemdf said, ignoring the RDM disk but still being able to manage the vm with Terraform would work for us.

[gvcgael]

Does anyone have any workaround ?

[sumitAgrawal007]

I have a PR out with this feature, people who are interested can try out the binary I have linked with the PR.
#1366