Sharing volumes with TrueCopy

You can share SI P-VOLs and S-VOLs with TC P-VOLs and S-VOLs. However, you cannot share SI S-VOLs with TC S-VOLs.

The write operation on the TC P-VOL takes more time when you share an SI P-VOL with a TC S-VOL.

For more information about splitting pairs, see Pair splitting methods.

Restrictions

The following restrictions apply:

• When you share an SI P-VOL with a TC S-VOL, if you split the SI pair during write I/Os to the TC P-VOL, only part of write I/Os might be written to the SI S-VOL. To keep data consistency in the SI S-VOL, stop I/Os to the TC P-VOL first, and then split the SI pair.
• You can use SI cascaded pairs as TC pairs. TC does not distinguish between node and leaf volumes in cascaded pairs. Both are considered S-VOLs.

  For more information about cascaded pairs, see Cascaded pairs.

• If you plan to Quick Restore the SI pair, you must first suspend the TC pair.
• You can perform a CTG pair-split on SI pairs that share volumes with TC S-VOLs.

  For more information about CTG pair-split for shared volumes, see Using consistency group pair-split with shared volumes

• If you want to use the SI S-VOL as the TI P-VOL, create the SI pair first, and then create the TI pair.

For more information about sharing SI and TC volumes, see the Hitachi TrueCopy® User Guide.

The following table describes ShadowImage operations when SI P-VOLs are shared with TC P-VOLs or S-VOLs.

The following table describes ShadowImage operations when SI S-VOLs are shared with TC P-VOLs.