You can change the for selected mirrored pairs on your .
When you select Metro mirror, the on the primary storage subsystem waits until data has been successfully copied to the secondary storage subsystem before
sending and I/O completion back to the system. If Global copy is selected, the controller on the primary storage subsystem sends an I/O completion to the host system before the data has
successfully been copied to the secondary storage subsystem.
Metro mirror – This mode offers the best chance of full data from the secondary storage subsystem in the event of a disaster, at the expense
of host I/O performance and is the preferred mode of operation.
Global copy – This mode offers faster host I/O performance but does not guarantee that data was successfully written to the before indicating a successful write to the host system.
Select the Add t o global mirror group check box if you want to make sure that writes to the secondary storage subsystem are completed in the same order as on the
primary storage subsystem.
Important:
Selecting this option might impact host I/O performance.
To continue the mirror creation process, click Next.