# flyteplugins.union.errors

Volume-specific runtime errors.

These subclass the :mod:`flyte.errors` taxonomy, so they keep flyte's
system/user recoverability classification (and their ``str()`` is the
message), while giving callers a stable ``flyteplugins.union.errors`` surface
to catch — e.g. ``except VolumeMountError`` or, more broadly, ``except
VolumeError`` (system) / ``except VolumeUsageError`` (caller misuse).

Each concrete type carries a fixed error ``code`` (surfaced on the flyte error
envelope) via the ``_code`` class attribute; subclasses just override it.
## Directory

### Errors

| Exception | Description |
|-|-|
| [`VolumeCommandError`](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumecommanderror/page.md) | A backend CLI invocation (e. |
| [`VolumeError`](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumeerror/page.md) | Base for Volume *system* failures — infra/runtime problems the caller. |
| [`VolumeMigrateNoop`](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumemigratenoop/page.md) | Metadata-store migration was requested to the store type already in use. |
| [`VolumeMountError`](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumemounterror/page.md) | The volume could not be mounted — the client exited prematurely, the. |
| [`VolumeMountTimeout`](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumemounttimeout/page.md) | The mount did not become a FUSE mountpoint within the timeout. |
| [`VolumeNoIndex`](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumenoindex/page.md) | An operation needs a published index, but the Volume has none. |
| [`VolumeNotForkable`](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumenotforkable/page.md) | Fork was requested on a Volume that is neither mounted nor has an index. |
| [`VolumeNotMounted`](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumenotmounted/page.md) | An operation that needs a live mount was called on an unmounted Volume. |
| [`VolumeStoreTypeNotSet`](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumestoretypenotset/page.md) | The Volume's ``metadata_store_type`` is unset and couldn't be resolved. |
| [`VolumeUnmountError`](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumeunmounterror/page.md) | The volume could not be unmounted (``fusermount`` kept returning EBUSY). |
| [`VolumeUsageError`](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumeusageerror/page.md) | Base for Volume *user* errors — caller misuse the caller can fix. |

## Subpages

- [VolumeCommandError](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumecommanderror/page.md)
  - Parameters
- [VolumeError](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumeerror/page.md)
  - Parameters
- [VolumeMigrateNoop](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumemigratenoop/page.md)
  - Parameters
- [VolumeMountError](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumemounterror/page.md)
  - Parameters
- [VolumeMountTimeout](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumemounttimeout/page.md)
  - Parameters
- [VolumeNoIndex](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumenoindex/page.md)
  - Parameters
- [VolumeNotForkable](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumenotforkable/page.md)
  - Parameters
- [VolumeNotMounted](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumenotmounted/page.md)
  - Parameters
- [VolumeStoreTypeNotSet](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumestoretypenotset/page.md)
  - Parameters
- [VolumeUnmountError](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumeunmounterror/page.md)
  - Parameters
- [VolumeUsageError](https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/volumeusageerror/page.md)
  - Parameters

---
**Source**: https://github.com/unionai/unionai-docs/blob/main/content/api-reference/integrations/union/packages/flyteplugins.union.errors/_index.md
**HTML**: https://www.union.ai/docs/v2/flyte/api-reference/integrations/union/packages/flyteplugins.union.errors/