cluster options are incompatible with type tmpfs

Error message

cluster options are incompatible with type tmpfs

What it means

Raised by handleTmpfsToMount when a `type: tmpfs` volume carries a `cluster:` options block. Cluster options belong to Swarm CSI cluster volumes; a tmpfs mount is node-local and in-memory, so the combination is rejected.

Source

Thrown at cli/compose/convert/volume.go:162

}

func handleTmpfsToMount(volume composetypes.ServiceVolumeConfig) (mount.Mount, error) {
	result := createMountFromVolume(volume)

	if volume.Source != "" {
		return mount.Mount{}, errors.New("invalid tmpfs source, source must be empty")
	}
	if volume.Bind != nil {
		return mount.Mount{}, errors.New("bind options are incompatible with type tmpfs")
	}
	if volume.Volume != nil {
		return mount.Mount{}, errors.New("volume options are incompatible with type tmpfs")
	}
	if volume.Image != nil {
		return mount.Mount{}, errors.New("image options are incompatible with type tmpfs")
	}
	if volume.Cluster != nil {
		return mount.Mount{}, errors.New("cluster options are incompatible with type tmpfs")
	}
	if volume.Tmpfs != nil {
		result.TmpfsOptions = &mount.TmpfsOptions{
			SizeBytes: volume.Tmpfs.Size,
		}
	}
	return result, nil
}

func handleNpipeToMount(volume composetypes.ServiceVolumeConfig) (mount.Mount, error) {
	result := createMountFromVolume(volume)

	if volume.Source == "" {
		return mount.Mount{}, errors.New("invalid npipe source, source cannot be empty")
	}
	if volume.Volume != nil {
		return mount.Mount{}, errors.New("volume options are incompatible with type npipe")
	}

View on GitHub (pinned to e9452d6e78)

Solutions

Remove the `cluster:` block from the tmpfs entry
If a cluster (CSI) volume was intended, use `type: cluster` and remove tmpfs-specific fields

Example fix

# before
volumes:
  - type: tmpfs
    target: /cache
    cluster: {}
# after
volumes:
  - type: tmpfs
    target: /cache

When it happens

Trigger: ServiceVolumeConfig with Type tmpfs and Cluster != nil during `docker stack deploy` conversion.

Common situations: Mixing CSI volume config into a tmpfs entry via copy-paste or YAML merge keys in Swarm stack files.

Related errors

AI-assisted analysis of docker/cli@e9452d6e78 (2026-08-01). Data as JSON: /data/errors/335e54356fe05a2e.json. Report an issue: GitHub.