VM Image Upload

PaaS Cloud lets you upload custom disk images to create vm-disk resources. This is useful when you need an OS image that is not available as a golden image in the catalog.

Prerequisites

virtctl installed. See Using virtctl.
kubeconfig access to the tenant namespace (contact the cloud team if needed).
A valid disk image file (e.g., .qcow2, .raw, .img).

Step 1: Create a vm-disk with Upload Source

In the dashboard, create a vm-disk and select Upload as the source:

source:
  upload: {}

Alternatively, create it via kubectl:

apiVersion: cdi.kubevirt.io/v1beta1
kind: DataVolume
metadata:
  name: my-custom-disk
spec:
  source:
    upload: {}
  pvc:
    accessModes:
      - ReadWriteOnce
    resources:
      requests:
        storage: 20Gi
    storageClassName: replicated

Step 2: Upload the Image

Use virtctl image-upload to stream the image into the vm-disk:

virtctl image-upload dv my-custom-disk \
  --image-path=/path/to/your-image.qcow2 \
  --size=20Gi \
  --storage-class=replicated \
  --access-mode=ReadWriteOnce \
  --insecure

Parameters

Flag	Description
`--image-path`	Path to the local image file.
`--size`	Requested PVC size. Must be at least as large as the image.
`--storage-class`	Storage class for the PVC. Default is `replicated` (LINSTOR/DRBD).
`--access-mode`	Access mode for the PVC. Typically `ReadWriteOnce`.
`--insecure`	Skip TLS verification (useful for internal endpoints).

Step 3: Use the Disk in a vm-instance

Once uploaded, reference the disk in your vm-instance:

disks:
- name: my-custom-disk

Upload Proxy Endpoint

For virtctl to know the correct upload endpoint, the cluster must expose the CDI upload proxy:

# Expose cdi-uploadproxy via the Platform Package
kubectl patch packages.cozystack.io cozystack.cozystack-platform --type=json \
  -p '[{"op": "add", "path": "/spec/components/platform/values/publishing/exposedServices/-", "value": "cdi-uploadproxy"}]'

# Provide the upload proxy URL
kubectl patch packages.cozystack.io cozystack.kubevirt-cdi --type=merge -p '{
  "spec": {
    "components": {
      "kubevirt-cdi": {
        "values": {
          "uploadProxyURL": "https://cdi-uploadproxy.example.org"
        }
      }
    }
  }
}'

Note

In PaaS Cloud, the upload proxy endpoint is typically pre-configured by the platform team. If uploads fail, contact cloud@metacentrum.cz.

Supported Image Formats

QCOW2 (.qcow2)
RAW (.)
VMDK (.vmdk)
ISO (.iso) — for optical disks

Troubleshooting

Problem	Solution
Upload hangs	Check that the CDI upload proxy is reachable. Verify the image file is not corrupt.
PVC too small	Increase `--size` to match or exceed the uncompressed image size.
Permission denied	Ensure your `kubeconfig` has write access to the tenant namespace.
Image boots slowly	Convert the image to RAW or optimize it with `virt-sparsify` before upload.

VM Image Upload

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