---
title: "Managing Glance images"
description: "Find out how to import, verify, share and delete images in Glance on SNC Cloud Platform, and create volumes from them with the OpenStack CLI"
url: https://docs.ovhcloud.com/en/guides/hosted-private-cloud/cloud-platform/glance-image-management
lang: en
lastUpdated: 2026-09-29
---
> For AI agents: the complete documentation index is available at https://docs.ovhcloud.com/en/llms.txt, the full documentation bundle is available at https://docs.ovhcloud.com/en/llms-full.txt.

# Managing Glance images

## Objective

Practical guide to importing, verifying and managing images in Glance (OpenStack's image catalogue service) on SNC Cloud Platform. Target audience: anyone who needs an image not in the default catalogue.

This guide covers an image's full lifecycle in Glance on this platform: import, verification, use for creating a volume or instance, visibility management, deletion — with the specifics of this platform, which complement generic OpenStack documentation.

## Requirements

- The `openstack` CLI configured (see the [Terraform guide](https://docs.ovhcloud.com/en/guides/hosted-private-cloud/cloud-platform/terraform.md) for `clouds.yaml`-based authentication).
- The `member` role, at minimum.
- A local machine with enough free disk space to stage the image being imported — the upload happens **from the local machine**, not server-side (see the "[Available import methods](#available-import-methods)" section).

## Instructions

### Available import methods

Glance offers several import methods. On this platform, only `openstack image create --file` (direct upload from the local machine) is supported — it is the recommended method:

| Method                                               | How it works                                                        | On this platform                                                                                                                                                                                                     |
| ---------------------------------------------------- | ------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `openstack image create --file` (direct upload, CLI) | The file is streamed **from the local machine** to Glance over HTTP | ✅ Recommended method, used in this guide. A \~7-8 GB file typically imports in 1 to 3 minutes depending on the local machine's upload bandwidth.                                                                     |
| `web_download`                                       | Glance downloads the image **server-side**, from a supplied URL     | ❌ Not functional on this platform, due to the network segmentation requirements tied to the ongoing SecNumCloud qualification (internal services have no outbound Internet access) — prefer the direct upload above. |
| Manual upload via the Horizon UI                     | Uploading a local file through the "Create Image" web form          | ⚠️ Not working yet. Use the CLI (`openstack image create --file`), which is fully supported.                                                                                                                         |
| `copy-image`                                         | Duplicates an image already present in Glance to another store      | ✅ Works (tested: `openstack image import <image> --method copy-image --store <store>`). Mainly useful in a multi-store context; this platform currently exposes a single store (`defaultstore`).                     |

### Step 1 — Listing existing images

Before importing anything, check whether an equivalent image already exists:

```bash
openstack image list -f table -c Name -c Status -c Visibility
```

Base catalogue generally available on this platform (varies by project): common Linux distributions (Debian, AlmaLinux, CentOS) as ready-to-use `OVH` images (cloud-init included). Any image outside this catalogue (Windows, an unlisted distribution, a specific appliance) needs to be imported manually.

### Step 2 — Importing an image

```bash
openstack image create \
  --disk-format <format> \
  --container-format bare \
  --private \
  --progress \
  --file /local/path/to/image \
  image-name
```

#### Picking the right `--disk-format`

| File type                                                    | `--disk-format` | Typical use                                                                |
| ------------------------------------------------------------ | --------------- | -------------------------------------------------------------------------- |
| Install ISO (Windows, a Linux distribution's installer)      | `iso`           | Boot from a virtual CD-ROM to launch an interactive or automated installer |
| QCOW2 disk image (QEMU native format, often with cloud-init) | `qcow2`         | Ready-to-use image, boots directly                                         |
| RAW disk image                                               | `raw`           | Ready-to-use image, no compression                                         |

`--container-format bare` fits nearly every case (no extra container metadata needed).

`--private` restricts the image's visibility to your project (see [step 5](#step-5--managing-an-images-visibility)).

#### Importing a large image

`--progress` shows a progress bar during the upload — useful for multi-GB files, where several minutes without visible feedback might otherwise suggest a stalled upload.

### Step 3 — Verifying an imported image

```bash
openstack image show image-name -f value -c status -c size -c checksum -c disk_format
```

`status` should read `active`. Any other value persisting (`queued`, `saving`) signals an import that is not progressing — see the "[Known pitfalls (troubleshooting)](#known-pitfalls-troubleshooting)" section.

### Step 4 — Creating a volume from an image

Two use cases, with different behaviour observed in practice:

#### Standalone volume (recommended)

```bash
openstack volume create --image image-name --size <size-GB> volume-name
```

Works reliably and quickly (tens of seconds for several GB). Prefer this method to verify that an image converts correctly to a volume before using it to create an instance.

:::warning
`<size-GB>` must be strictly greater than the image's **virtual size** (Glance's `virtual_size`), not its compressed size on disk. An image weighing a few hundred MB can have a virtual size of 15-20 GB once decompressed.
:::

#### Volume created alongside an instance (`server create --block-device`)

```bash
openstack server create \
  --block-device uuid=<image-id>,source_type=image,destination_type=volume,volume_size=<size-GB> \
  ...
```

:::warning
**Good practice**: creating **multiple** `source_type=image` block devices at once in a single `server create` call can leave the instance in `task_state=scheduling`/`spawning` for longer than expected before reaching `ACTIVE`. The recommended approach on this platform is to **pre-create each volume separately** (fast and reliable, method above), then reference them in `server create` with `source_type=volume` (not `image`):

```bash
openstack server create \
  --block-device uuid=<volume-id>,source_type=volume,destination_type=volume,boot_index=0 \
  ...
```

:::

### Step 5 — Managing an image's visibility

```bash
openstack image set --private image-name   # visible only to the current project
openstack image set --shared image-name    # explicit sharing with specific projects

# once shared, grant a specific project access to it:
openstack image add project image-name <target-project-id>
```

`--private` is the recommended default for an image imported for a one-off use (test, Windows VM). `--shared` works as expected on this platform to share an image with specific projects. `public` visibility (accessible to every project on the platform) is not available.

### Step 6 — Deleting an image

```bash
openstack image delete image-name
```

An image cannot be deleted while a volume or instance still directly depends on it. Whether a dependency remains depends on the attachment method: a volume already created from the image no longer depends on it. Check for active usage before deleting:

```bash
openstack volume list --property image_id=<image-id> -f table
```

### Known pitfalls (troubleshooting)

| Symptom                                                                                                                   | Explanation                                                                                                                                                                                                            | Recommendation                                                                                                                                                                                         |
| ------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| Import stuck in `queued` status, no progress                                                                              | `web_download` attempted from an external URL — not a supported method on this platform (see [available import methods](#available-import-methods))                                                                    | Use direct upload from the local machine instead (`openstack image create --file`, [step 2](#step-2--importing-an-image))                                                                              |
| Horizon's "Create Image" form is not available                                                                            | Not working yet on this platform                                                                                                                                                                                       | Use the CLI (`openstack image create --file`)                                                                                                                                                          |
| An import error's detail (`/v2/tasks/<id>`) is not directly viewable                                                      | The `/tasks` API is not exposed on this platform                                                                                                                                                                       | Check the high-level status via `openstack image show`; for finer diagnostics, [contact OVHcloud support](https://www.ovhcloud.com/en-gb/support-levels/)                                              |
| `Block Device <id> is not bootable` when creating an instance on a volume created from an image                           | Rare with a standard image (the `bootable` flag is normally set automatically by Cinder during an image→volume conversion) — mostly concerns **blank** volumes (`source_type=blank`), which are outside Glance's scope | See the [Creating a Windows Server VM](https://docs.ovhcloud.com/en/guides/hosted-private-cloud/cloud-platform/create-windows-server-vm.md) guide for the blank-volume case                            |
| Instance taking a while to reach `ACTIVE` with several `source_type=image` block devices in the same `server create` call | Converting several images to volumes simultaneously at boot time is not the recommended approach on this platform                                                                                                      | Pre-create each volume separately via `openstack volume create --image`, then reference the volumes (`source_type=volume`) in `server create` — see [step 4](#step-4--creating-a-volume-from-an-image) |
| `Image virtual size is XGB and doesn't fit in a volume of size YGB`                                                       | `--size`/`volume_size` smaller than the image's actual virtual size                                                                                                                                                    | Increase the size with a comfortable margin above the `virtual_size` reported by Glance                                                                                                                |

## Go further

[Creating a Windows Server VM](https://docs.ovhcloud.com/en/guides/hosted-private-cloud/cloud-platform/create-windows-server-vm.md) — importing an ISO, full use case including blank volumes; same platform, same import limitations.

[Terraform guide](https://docs.ovhcloud.com/en/guides/hosted-private-cloud/cloud-platform/terraform.md) — the `data "openstack_images_image_v2"` pattern for reusing an existing image without recreating it.

Official OpenStack Image (Glance) CLI documentation: [docs.openstack.org — Image v2](https://docs.openstack.org/python-openstackclient/latest/cli/command-objects/image/v2/index.html).

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