Create and use custom disk images

This guide shows you how to create custom disk images, boot disks from them, and manage custom disk images using the evroc CLI and API.

Prerequisites

Access to an evroc organization and project
evroc CLI installed and configured

Create an evroc bucket in the same project as the boot disks that will use it. Then create a bucket service account with access to that bucket. Upload the disk image as a .qcow2, .vhdx or .raw file to that bucket. See the storage API guide for further instructions.

N.B. You must use a BucketServiceAccount, and not a regular ServiceAccount, to access the bucket. Whereas ServiceAccounts allow you to grant fine-grained permissions, BucketServiceAccounts only allow granting "all or nothing" permissions (you either have complete access to - and control over - the bucket, or you don't).

Create a custom disk image

Create a custom disk image that references the uploaded file.

Create a custom disk image using the CLI

evroc compute customdiskimage create mydiskimage \
  --bucket=my-bucket \
  --service-account=my-bucket-service-account \
  --path=images/mydiskimage.qcow2 \
  --architecture=amd64 \
  --size-amount=20 \
  --size-unit=GB

Create a custom disk image using the API

curl -X POST https://api.evroc.com/compute/v1beta2/projects/{projectID}/regions/{regionName}/customDiskImages \
  -H "Content-Type: application/json" \
  -d '{
    "apiVersion": "compute/v1beta2",
    "kind": "CustomDiskImage",
    "metadata": { "id": "mydiskimage" },
    "spec": {
      "architecture": "amd64",
      "defaultDiskSize": { "amount": 20, "unit": "GB" },
      "source": {
        "bucketRef": "/storage/projects/{projectID}/regions/{regionName}/buckets/my-bucket",
        "serviceAccountRef": "/storage/projects/{projectID}/regions/{regionName}/bucketServiceAccounts/my-bucket-service-account",
        "path": "images/mydiskimage.qcow2"
      }
    }
  }'

See Create a Custom Disk Image in the API reference.

List custom disk images

List all custom disk images in your project:

evroc compute customdiskimage list

Use evroc compute customdiskimage get <disk_image_name> for detailed information.

See List Custom Disk Images in the API reference.

Create a disk from a custom disk image

You can create a boot disk from a custom disk image.

Create a boot disk from a custom disk image using the CLI

evroc compute disk create mynewdisk \
  --custom-image=mydiskimage \
  --zone=a

If you don't specify a disk size, it defaults to the custom disk image's defaultDiskSize.

Create a boot disk from a custom disk image using the API

curl -X POST https://api.evroc.com/compute/v1beta2/projects/{projectID}/regions/{regionName}/disks \
  -H "Content-Type: application/json" \
  -d '{
    "apiVersion": "compute/v1beta2",
    "kind": "Disk",
    "metadata": { "id": "mynewdisk" },
    "spec": {
      "source": {
        "type": "image",
        "diskImageRef": "/compute/projects/{projectID}/regions/{regionName}/customDiskImages/mydiskimage"
      },
      "placement": { "zone": "a" }
    }
  }'

See Create a Disk in the API reference.

Delete a custom disk image

Delete a custom disk image you no longer need. The custom disk image can't be deleted if any disks still reference it.

evroc compute customdiskimage delete mydiskimage

See Delete a Custom Disk Image in the API reference.

Debugging

If a VM cannot be started from a custom disk image, check the console logs.

evroc User Documentation