You need to prepare a data-reduced volume (V-VOL with capacity saving enabled, DRS-VOL) for use as the S-VOL of a GAD pair if the volume has capacity saving enabled and has assigned pages.
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Perform LDEV formatting on the volume you want to use as the S-VOL.
If the volume to be used as the S-VOL is a volume with the vClone Parent or vClone attribute, do not perform LDEV formatting. If you perform LDEV formatting, the management information of Thin Image Advanced is initialized, so the virtual clone functionality will become unavailable.If you create a pair when the S-VOL has assigned pages, the initialization is performed during the copy operation, which might increase the required time for copying or increase the processor operating rate. Therefore, create a pair after performing LDEV formatting unless you use the virtual clone functionality of Thin Image Advanced. If you use the virtual clone functionality of Thin Image Advanced, you create a pair when assigned pages already exist. Therefore, consider the impact on the time required for copying and the operating time.
- Set the capacity saving mode that you want to use on the S-VOL to the mode that satisfies your user requirements.
If the volume you want to use as the S-VOL is a volume with the vClone attribute, you do not need to set the capacity saving mode (inline mode or post-process mode) because the settings for the parent volume of the Thin Image Advanced pair are applied. For VSP One B85, if the volume you want to use as the S-VOL is a DRS-VOL with capacity saving disabled, capacity saving mode is not applied.
- Set the post-process mode if the user requirement is to suppress the impact on
the I/O performance.
Using this mode, the S-VOL requires the effective pool capacity to be as large as the P-VOL because capacity saving is performed after the pair is created.
- Set the inline mode if the user requirement is to suppress the required pool capacity.
The required time for copying might be longer or the processor operating rate might be greater than that in the post-process mode. Consider applying the post-process mode to suppress the required time or processor operating rate.
- Set the post-process mode if the user requirement is to suppress the impact on
the I/O performance.