StorPool Volume Attachment

https://blueprints.launchpad.net/nova/+spec/libvirt-storpool-volume-attach

There are various Nova volume drivers providing access to Cinder volumes using specific types of storage, such as LVM, RBD, etc. The purpose of this blueprint is to add a driver supporting the volumes defined in a StorPool cluster.

Problem description

StorPool is distributed data storage software running on standard x86 servers. StorPool aggregates the performance and capacity of all drives into a shared pool of storage distributed among the servers. Within this storage pool the user creates thin-provisioned volumes that are exposed to the clients as block devices. StorPool consists of two parts wrapped in one package - a server and a client. The StorPool server allows a hypervisor to act as a storage node, while the StorPool client allows a hypervisor node to access the storage pool and act as a compute node. In OpenStack terms the StorPool solution allows each hypervisor node to be both a storage and a compute node simultaneously.

Use Cases

As a Deployer, I want to be able to attach StorPool volumes managed by Cinder to my instances for persistent storage, taking advantage of StorPool’s performance and scalability during the instance operation, instant attachment of the volume to the hypervisor at instance startup, and seamless migration of the instance to a different hypervisor.

Project Priority

None.

Proposed change

The proposed driver will make use of the StorPool API (based on JSON over HTTP) to attach and detach volumes defined in the StorPool cluster and already known to Cinder.

Alternatives

None.

Data model impact

None.

REST API impact

None.

Security impact

None.

Notifications impact

None.

Other end user impact

None.

Performance Impact

The requests to attach or detach a volume will be passed on to the StorPool JSON-over-HTTP API.

Other deployer impact

None.

Developer impact

None.

Implementation

Assignee(s)

Primary assignee:

Peter Penchev <openstack-dev@storpool.com>

Other contributors:

None

Work Items

  • Write the nova.virt.libvirt.storpool driver to attach and detach volumes.

  • Write tests for the StorPool driver.

  • Provide a CI setup for the StorPool driver.

Dependencies

The StorPool driver for Cinder for handling StorPool volumes: https://blueprints.launchpad.net/cinder/+spec/storpool-block-driver

Testing

Since the test setup requires an operational StorPool cluster, the unit tests will mostly use mocking to simulate the operations. A separate continuous integration environment will be set up by StorPool and access to it will be provided for running automated CI tests.

Documentation Impact

Using the StorPool driver will be documented.

References

The StorPool distributed storage software: http://storpool.com/