Out-of-band RAID configuration using Cisco UCS drivers

https://bugs.launchpad.net/ironic/+bug/1526362

This blueprint proposes to implement out-of-band RAID configuration interface for Cisco UCS drivers. This implementation supports configuration of Cisco UCS Manager (UCSM) managed B/C/M-series servers.

Problem description

Currently pxe_ucs and agent_ucs drivers don’t support RAID configuration on UCSM managed servers.

Proposed change

It proposes implementing the RAID interface as described by the parent spec [1] for UCS drivers.

List of changes required:

  • ucs.raid.RAIDInterface for RAID configuration operations

    The following methods will be implemented:

    • validate
    • create_configuration
    • delete_configuration

    validate() method validates the required UCS parameters for OOB RAID configuration. Also calls validate() of the super class to validate json schema. create_configuration and delete_configuration operations are implemented as asynchronous RAID configuration deployment operations by UCS drivers. UcsSdk/UCS-API asynchronously deploys the RAID configuration on the target node. UCS driver(s) sends the RAID configuration simultaneously to the target node when the operation is invoked, but UCS Manager would not deploy the configuration simultaneously on the target node. UCS Manager accepts the RAID configuration and deploys it as part of UCS Manager FSM deploy state. Hence there will be delay between, when the operation is invoked and when the RAID configuration is deployed. To know the deploy status, we need to query the FSM status using UcsSdk API. These methods return states.CLEANWAIT. New driver periodic task will be added to fetch the UCSM FSM status of these operations. This periodic task is enabled only if pxe_ucs, agent_ucs drivers are enabled in the conductor.

  • RAID management changes:

    Controlling the RAID configuration is creating storage-profile ManagedObject and associating with the Server object in UCS Manager 2.4. Earlier version of UCSM requires to configure LocalDiskConfigPolicy and associate with respective service-profile ManagedObject. The service-profile information is captured as part of node driver_info properties. UcsSdk provides RAIDHelper interface, which actually creates the required policies specified above. UCS driver uses this interface and makes appropriate calls to create_config and delete_config operations.

Alternatives

Operator can change the RAID configuration manually whenever required after putting the node to MANAGEABLE state. But this has to be done for each node.

Data model impact

None

State Machine Impact

None

REST API impact

None

Client (CLI) impact

None

RPC API impact

None

Driver API impact

None

Nova driver impact

None

Ramdisk impact

N/A

Security impact

None

Other end user impact

None

Scalability impact

None

Performance Impact

None

Other deployer impact

None

Developer impact

None

Implementation

Assignee(s)

Primary assignee: saripurigopi

Work Items

  • Add UcsRAIDManagement inheriting from base.RAIDInterface for ucs drivers.
  • Writing and unit-test cases for RAID interface of ucs drivers.
  • Writing configuration documents.

Dependencies

  • UcsSdk to support RAID configuration utility

Testing

Unit-tests will be implemented for RAID interface of ucs driver.

Upgrades and Backwards Compatibility

Adding RAID interface support for ucs drivers will not break any compatibility with either REST API or RPC APIs.

Documentation Impact

  • Writing configuration documents.

References

[1]New driver interface for RAID configuration: https://review.openstack.org/173214