Fix incorrect disk sizes during VMware VM import

[susesamu]

Problem:
When importing virtual machines from VMware vCenter, the vm-import-controller determines disk sizes using nfc.LeaseItem.Size. In some VMware environments this value represents the total provisioned capacity of the VM, not the size of the individual disk.

As a result, each imported disk may incorrectly receive the aggregate VM size, causing PVCs to be over-provisioned and migrations to fail due to insufficient storage.

Solution:
Disk capacities are now determined using the VM hardware configuration retrieved from: mo.VirtualMachine.Config.Hardware.Device For each VirtualDisk, the code reads: VirtualDisk.CapacityInKB and maps disks to lease items using the busNumber.

Related Issue:
harvester/harvester#10167

Test plan:

1. Create a VM with multiple disks with different sizes.
2. Create a VirtualMachineImport resource
3. Check the disk sizes created in Harvester
4. Disk sizes should now match the original VMware disk capacities.

Observations
on the previous PR, we couldn't match the key, so we now matching the busNumber since is unique per controller instance in hardware model.

[Copilot]

Pull request overview

Adjusts VMware VM import logic so disk sizes are derived from the VM’s hardware configuration (per-disk capacity) rather than relying on NFC lease item sizes, which can represent aggregate VM capacity in some environments.

Changes:

• Retrieves config.hardware.device from vCenter and builds a lookup of VirtualDisk devices.
• Determines per-disk size using VirtualDisk.CapacityInKB (bytes = KB * 1024) and falls back to lease Size if mapping fails.
• Adds parseDeviceId helper to map lease items to hardware disks by (bus, unit).

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[ibrokethecloud]

i was able to verify the disk sizes via a simple unit test

    /Users/gauravmehta/go/src/github.com/harvester/vm-import-controller/pkg/source/vmware/client_test.go:621: disk from vm obj disk-0.vmdk: size 42949672960
    /Users/gauravmehta/go/src/github.com/harvester/vm-import-controller/pkg/source/vmware/client_test.go:622: disk from lease disk-0.vmdk: size 48318382080
    /Users/gauravmehta/go/src/github.com/harvester/vm-import-controller/pkg/source/vmware/client_test.go:621: disk from vm obj disk-1.vmdk: size 5368709120
    /Users/gauravmehta/go/src/github.com/harvester/vm-import-controller/pkg/source/vmware/client_test.go:622: disk from lease disk-1.vmdk: size 48318382080

the vm obj does reflect the correct disk size, compared to the lease object.

[votdev]

LGTM

... but missing some unit tests, e.g. for parseDeviceId and some comments to show what the field contains. E.g. i'm missing the explanation of the schema that is used by DeviceId. Such documentation will make life easier in the future.

[ibrokethecloud]

minor nit, should we also log the error here so we know which device was skipped?

[votdev]

I don't think this is necessary because some lines below where the parseDeviceId function is called a log message is generated when the code is using the fallback path:

if diskSize == 0 {
				// fallback to lease size if mapping failed
				logrus.WithFields(logrus.Fields{
					"name": vm.Name, "namespace": vm.Namespace,
					"path":     i.Path,
					"deviceId": i.DeviceId,
					"size":     i.Size,
				}).Warn("Failed to map lease VMDK to VirtualDisk capacity; falling back to lease item size")
				diskSize = i.Size
			}

This log message contains all relevant info that is necessary to know what happened.

[votdev]

@Mergifyio backport v1.8

[mergify]

backport v1.8

✅ Backports have been created

Details

• #141 Fix incorrect disk sizes during VMware VM import (backport #140) has been created for branch v1.8