Start CPC

The Start CPC operation starts the CPC object designated by {cpc-id}. The target CPC object must be enabled for DPM.

HTTP method and URI

POST /api/cpcs/{cpc-id}/operations/start

In this request, the URI variable {cpc-id} is the object ID of the target CPC object.

Response body contents

Once the operation is accepted, the response body contains a JSON object with the following fields:

Field name Type Description
job-uri String/ URI URI that may be queried to retrieve job status or used to request cancellation of the operation.

Asynchronous result description

Once the operation has completed, a job-completion notification is sent and results are available for the asynchronous portion of this operation. These results are retrieved using the Query Job Status operation directed at the job URI provided in the response body.

The result document returned by the Query Job Status operation is specified in the description for the Query Job Status operation. When the status of the job is "complete", the results include a job completion status code and reason code (fields job-status-code and job-reason-code) which are set as indicated in Job status and reason codes. The job-results field is null when this operation is successful. When it is partially successful or not successful, the job-results field contains an object with the following field:
Field name Type Description
message String The message text describing the detailed error that occurred when the operation was partially successful or not successful.

Description

Start CPC is a process that makes a CPC operational, which means either:

  • The CPC is ready to have a control program or operating system loaded, or
  • The CPC has loaded and is running a control program or operating system.

Start CPC makes a CPC operational by:

  • Using predefined information to set the operational capabilities and characteristics of the CPC
  • Checking the current status of the CPC, and then performing only the operations necessary to make it operational.

So, using Start CPC is not limited to starting the system. Using Start CPC is recommended whenever you want to make the CPC or its partition objects operational.

A complete start starts the CPC and its partition objects completely in a single step. The result of a complete start is an operational CPC with partition objects loaded and running operating systems. The current status of the CPC and its partition objects determines which operations are performed during the start to make them operational. The start may include:

  1. Turning CPC power on.
  2. Performing a power-on reset, this includes allocating system resources to the CPC.
  3. Then starting partition objects to support multiple images. Starting each partition object includes:
    1. Initializing it.
    2. Allocating system resources to it.
    3. Loading it with a control program or operating system.

Because the status of the CPC and its partition objects determines which operations must be performed during the start to make them operational, one or more operations listed above may not be performed during the start. For example:

  • Starting the CPC does not perform a power-on reset if the CPC has already been power-on reset and the desired applicable settings, such as the operating mode and active input/output configuration data set (IOCDS), are already in effect.
  • Starting the CPC does not perform any operations if the CPC is already operational and all desired settings are already in effect.

When the operation is initiated, a 202 (Accepted) status code is returned. The response body includes a URI that may be queried to retrieve the status of the operation. See Query Job Status for information on how to query job status. When the operation has completed, an asynchronous result message is sent, with Job Status and Reason Codes described in Job status and reason codes.

This operation supports cancellation of its asynchronous processing identified by the Job URI provided in the response body. Use the Cancel Job operation to request cancellation. Note that it may no longer be possible to cancel the job when the cancellation request is issued. The job status and reason codes will indicate whether the job was canceled or ran to completion.

Authorization requirements

This operation has the following authorization requirements:
  • Object-access permission to the CPC object designated by {cpc-id}
  • Action/task permission for the Start task.

HTTP status and reason codes

On success, HTTP status code 202 (Accepted) is returned and the response body is provided as described in Response body contents.

The following HTTP status codes are returned for the indicated errors, and the response body is a standard error response body providing the reason code indicated and associated error message.

HTTP error status code Reason code Description
400 (Bad Request) Various Errors were detected during common request validation. See Common request validation reason codes for a list of the possible reason codes.
403 (Forbidden) 1 The API user does not have the required permission for this operation.
404 (Not Found) 1 The object ID in the URI ({cpc-id}) does not designate an existing CPC object, or the API user does not have object-access permission to the object.
409 (Conflict) 5 The operation cannot be performed because the CPC object designated by {cpc-id} is currently not enabled for DPM.
329 The operation cannot be performed because the CPC designated by the request URI is an unmanaged CPC, which is not supported by this operation.
500 (Server Error) 280 An IO exception occurred during the scheduling of the asynchronous request.
503 (Service Unavailable) 1 The request could not be processed because the HMC is not communicating with the SE needed to perform the requested operation.

Additional standard status and reason codes can be returned, as described in Invoking API operations.

Job status and reason codes

Job status code Job reason code Description
204 (No Content) N/A Operation completed successfully.
500 (Server Error) 263 Operation failed, was canceled, or was rejected due to the current CPC status. The CPC status is unknown. Refer to the message parameter in the error response body for details.

Additional standard status and reason codes can be returned, as described in Invoking API operations.

Usage note

This operation starts a CPC that is enabled for DPM only. If the targeted CPC object is not enabled for DPM, the Activate CPC operation may be used instead. Refer to Activate CPC for details.