Workflow for operating ShadowImage pairs

REST API Reference Guide for Virtual Storage Platform 5000, Virtual Storage Platform E Series, and Virtual Storage Platform G/F Series

Part Number
The following shows the ShadowImage functions that can be run by the REST API:
  • Getting information about copy groups

    Obtains a list of copy groups registered in the target storage system. You can also obtain information about a specific copy group.

  • Getting pair status and configuration information

    Obtains a ShadowImage pair status and configuration information. You can check if a pair operation is complete. You can also obtain pair information in units of copy groups.

    If the copy group in which the target ShadowImage pair is registered contains a ShadowImage pair that was created or deleted by using another REST API server or software other than the REST API, correct information about that pair might not be obtained. In such a case, update the information about the pairs to the most recent information before you obtain information.

  • Creating a pair

    Creates a new ShadowImage pair in a copy group of the target storage system. A copy group is a group made up of copy pairs. Each copy group consists of a device group made up of primary volumes, and a device group made up of secondary volumes. If the copy group is not already created, the copy group and its corresponding device groups are automatically created. You will be able to perform operations in units of copy groups by registering ShadowImage pairs in a copy group.

    To create a pair in a new copy group:

    To create a pair in an existing copy group:

  • Splitting a pair

    Splits a ShadowImage pair and enables read and write access for a secondary volume. You can also split pairs in units of copy groups.

  • Resynchronizing a pair

    Resynchronizes a split ShadowImage pair based on the primary volume. Even during resynchronization, you can access the P-VOL. You can also resynchronize pairs in units of copy groups.

  • Resynchronizing a pair by a restore

    Resynchronizes a split ShadowImage pair based on a secondary volume. During resynchronization by a restore, you cannot access the P-VOL. You can also perform a restore in units of copy groups.

  • Deleting a pair

    Deletes a ShadowImage pair that is unnecessary. If you delete a pair, the pair is dissolved. The data in the primary volume and secondary volume remains unchanged. In addition, if you delete all the ShadowImage pairs in a copy group, the copy group and the device group included in the copy group are automatically deleted. You can also delete pairs in units of copy groups.

    You can delete a pair at any time regardless of the pair status. However, if you delete a pair while the pair status is being changed, the pair might be deleted before its status is changed, and the request to change the pair status might time out.

Specifying Job-Mode-Wait-Configuration-Change in the request header

During the creation, splitting, and resynchronizing of pairs, if multiple asynchronous processing requests are issued at the same time, jobs might get stuck and the job status might not change to Completed because data copying takes a long time. In such cases, specify Job-Mode-Wait-Configuration-Change:NoWait in the request header so that the job status changes to Completed without waiting for data copying to finish, and the next job starts. At this time, data copying continues even after job execution ends. To check whether data copying has finished, check the pair status of the target resource instead of the job status. For details about the pair status, see the description of the pair status transitions.