Service remains at "Starting" forever when using convoy-gluster storage pool

I’ve set up a Convoy-Gluster storage pool successfully in Rancher 1.0. I’d like to use this storage-pool to store my Gitlab data on.
When mapping the volumes of gitlab-data to host-folders the stack starts and works without issues but when mapping it to the convoy-gluster the service gitlab-server stays forever at Starting.
What am I doing wrong?

This is my docker-compose.yml:

gitlab-server:
  hostname: my.host.com
  ports:
  - 8101:22/tcp
  - 8100:8100/tcp
  labels:
    io.rancher.sidekicks: gitlab-data
  environment:
    GITLAB_OMNIBUS_CONFIG: |
      external_url 'http://my.host.com:8100'
      gitlab_rails['gitlab_shell_ssh_port'] = 8101
  image: gitlab/gitlab-ce:latest
  volumes_from:
  - gitlab-data

gitlab-data:
  labels:
    io.rancher.container.start_once: 'true'
  entrypoint:
  - /bin/true
  hostname: gitdata
  image: gitlab/gitlab-ce:latest
  volumes:
  - gitlab:/etc/gitlab
  - gitlab:/var/log/gitlab
  - gitlab:/var/opt/gitlab
  volume_driver: convoy-gluster

This is my rancher-compose.yml:

gitlab-server:
  scale: 1
  retain_ip: true

gitlab-data:
  scale: 1
  retain_ip: true

It looks like you are hitting this issue.