Workflow for operating global-active device 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 global-active device pair operation, which is performed in an environment that uses the REST API, is divided into normal operation and maintenance operation.

If you perform operations on or get information about global-active device pairs, specify Remote-Authorization for the request header.

Normal operation

The following figure shows the workflow for the normal operation.

Creating a pair
Create a pair, and then copy all of the data in the P-VOL to the S-VOL. The pair is duplicated. Create a pair in a new copy group (mirror), or add a pair to an existing copy group (mirror). A copy group is a group made up of copy pairs. Each copy group consists of a device group made up of P-VOLs, and a device group made up of S-VOLs.
Getting information about a copy group or pair
You can perform operations on the pair in units of copy groups or pairs.
Deleting a pair
Suspend the pair in advance, and then dissolve the pair status of the volumes.

Maintenance operation

You can use the REST API to stop the storage systems used by global-active device as planned and to perform maintenance work.

The following figure shows the workflow for performing maintenance work of the primary site.

Suspending a pair (by specifying the S-VOL)
Suspend the status of a pair that is duplicated. I/O is switched to the secondary site.
Stopping I/O for the P-VOL as planned
Stop I/O for the P-VOL.
Maintenance work
At the primary site, upgrade the micro version or perform other maintenance work.
Resynchronizing a pair (by specifying the S-VOL) (swap resync)
After the maintenance work, resynchronize the differential data generated during stop of the P-VOL. Switch the P-VOL and the S-VOL, and then copy the data of the switched P-VOL to the S-VOL to resynchronize the pair.

Resynchronization can be performed in units of copy groups or pairs. If you want to register pairs to a consistency group during resynchronization, perform resynchronization in units of copy groups. Do not perform resynchronization in units of pairs.

Resynchronizing a pair (by specifying the P-VOL) (swap resync)
If necessary, switch the switched P-VOL and S-VOL.
Restarting I/O for the P-VOL
Restart I/O for the P-VOL.

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.