Deleting GAD pairs

Pair deletion deletes the pair relationship between the P-VOL and the S-VOL. The data in each volume is not affected. When you delete a pair, you can specify the volume (P-VOL or S-VOL) that will receive update data from the host after the pair is deleted. The virtual LDEV ID of the unspecified volume is deleted, and the GAD reserve attribute is set for the specified volume.

The following table specifies the required conditions for the volume that will continue to receive update data from the host after deleting the pair.

If an I/O is issued to a volume with the virtual LDEV ID deleted by deleting a GAD pair, the access might be lost depending on the server. Before deleting the GAD pair, take the host path to the volume whose I/O mode is Block offline on the server side.

You must suspend the GAD pair before you can delete it. If you suspend a GAD pair by specifying an S-VOL, you must delete the GAD pair by specifying the S-VOL. If you suspend a GAD pair by specifying a P-VOL, you must delete the GAD pair by specifying the P-VOL.

After the GAD pair is deleted, the data on the P-VOL and S-VOL is not synchronized. To prevent viewing a duplicated volume with the same virtual LDEV ID but asynchronous data on the server, the virtual LDEV ID of the LDEV that does not continue I/O is deleted. When the virtual LDEV ID is deleted and the GAD reserve attribute is assigned to the volume, the server cannot recognize the volume.

If you want to re-create a GAD pair using a volume that was deleted from a pair, re-create the GAD pair from the storage system with the volume that was specified when you deleted the GAD pair. For example, if you deleted the GAD pair by specifying the P-VOL, re-create the GAD pair from the primary storage system. If you deleted the GAD pair by specifying the S-VOL, re-create the GAD pair from the secondary storage system.

pairsplit -g oraHA -S -IH0