The Remote FlashCopy® function enables you to perform operations on Compatible FlashCopy® relationships on the TCz secondary storage system. These operations are performed from the host connected to the TCz primary storage system. This function can be used for both Compatible FlashCopy® V2 and CFCSE relationships.
The Remote FlashCopy® function operates as follows:
- A Compatible FlashCopy® operation command is issued to the TCz P-VOL.
- The command is transmitted from the Main Control Unit (MCU) to the Remote Control Unit (RCU).
- The secondary storage system identifies the TCz S-VOL as a Compatible FlashCopy® S-VOL, and then performs a Remote FlashCopy® operation (for example, it creates a relationship, releases a relationship, or displays information about a relationship).
When you use the Remote FlashCopy® function and establish the Compatible FlashCopy® relationship with the FREEZE option, you can temporarily suspend writing to the P-VOL of the TCz pair. For details, see Sharing a Compatible FlashCopy® S-VOL and a TCz volume.
You cannot perform the Remote FlashCopy® function in the following cases:
- The Compatible FlashCopy® operation command is not issued to the TCz P-VOL.
- The Compatible FlashCopy® source volume is not the TCz secondary volume.
- You specify an extent when you establish a relationship. You cannot use extents to establish a relationship for dataset copying.
- The TCz S-VOL status is Simplex (unpaired).
- The TCz S-VOL status is Pending.
- The TCz S-VOL status is Duplex or Suspend, and the TCz P-VOL status is Simplex or Pending.
The following figure shows the Remote FlashCopy® function. If the CFCSE license is not installed on the primary storage system, only the CFCSE relationships on the secondary storage system are released.