What is Flocker?

Flocker is an open-source container data volume orchestrator for your Dockerized applications.

By providing a tool that migrates data along with containers as they change hosts, Flocker gives Ops teams the tools they need to run containerized stateful services like databases in production.

Unlike a Docker data volume which is tied to a single server, a Flocker data volume, called a dataset, is portable and can be used with any container in your cluster.

Flocker manages Docker containers and data volumes together. When you use Flocker to manage your stateful microservice, your volumes will follow your containers when they move between different hosts in your cluster.

Native docker 'vs' Flocker
Flocker lets you move a container and its volume together between hosts
Flocker works with container manager's like Docker Swarm, Kubernetes and Mesos
Flocker moves a container to new host and reattaches its existing data volume

Container Manager and Storage Integrations

Flocker is designed to work with the other tools you are using to build and run your distributed applications. Flocker can be used with popular container managers or orchestration tools like Docker, Kubernetes, Mesos.

For storage, Flocker supports block-based shared storage such as Amazon EBS, or OpenStack Cinder so you can choose the storage backend that is best for your application. Read more about choosing the best storage backend for your application. You can also use Flocker to take advantage of pre-defined storage profiles that are offered by many storage providers. Find out more about Flocker’s storage profile support.

What are the storage options?

Flocker allows you to use network-attached shared storage, like Amazon EBS or OpenStack Cinder, for your application’s storage layer. Use the chart below to explore our ever-growing list of storage capabilities, or contact us if you need help evaluating Flocker for your production deployment or don't see an option you'd like.

Supported configurations
Supported storage environments
  • AWS Elastic Block Storage (EBS)
  • Google Persistent Disk
  • OpenStack Cinder with any supported backend
  • EMC ScaleIO, XtremeIO, VMAX, VNX/Unity
  • VMware vSphere and vSAN
  • NetApp OnTap
  • Dell Storage SC Series
  • HPE 3PAR StoreServ and StoreVirtual (with OpenStack only)
  • Pure Storage
  • Huawei OceanStor
  • Hedvig
  • NexentaEdge
  • ConvergeIO
  • Saratoga Speed
  • Tintri
  • Ceph (Expiremental)
Supported cloud providers and on-premise environments
  • AWS
  • Google
  • OpenStack private clouds
  • Private data centers with a supported storage environment
Max number of data volumes per physical or virtual host About 25 depending on cloud platform
Supported file system Ext4
Supported operating systems
  • Ubuntu
  • CentOS 7
  • Red Hat Enterprise Linux 7
  • CoreOS (Coming Soon)
Data volume migrations between servers in the same data center*
Failover support within a data center*
Data volumes migrations between servers in different data centers*

* For the purpose of this table, a data center is defined as a:

  • Set of VMs in an AWS AZ with access to attach the same EBS volumes, or
  • Set of VMs connected to the same OpenStack Cinder backend,
  • Set of machines connected to the same supported physical storage array.

Works with your container stack


Works with your storage

Amazon Web Services
Google Cloud Platform
hewlett packard enterprise
Saratoga Speed
Pure Storage FlashArray//m
Persons Name from Job Title and Company Name

‘We decided to use lightweight Docker containers for a major new initiative, but as we investigated options, we quickly realized that without a solution for persistent data management in containers, we wouldn’t be able to achieve the density benefits we were after. When we saw Flocker from ClusterHQ, we knew we had found a compelling and open-source solution.’

Marco HochstrasserCEO, Swisscom Cloud Lab

Flocker volume manager works with

(and anything else that works on Linux)

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