A method for managing activity of a data storage system including a
primary storage facility and a secondary storage facility. The method
includes mirroring a first logical unit in the primary facility on a
second logical unit in the secondary facility, and receiving a command to
perform a data storage management activity on the first logical unit. The
method further includes synchronizing the second logical unit with the
first logical unit responsive to the command, and performing the command
on the first logical unit and the second logical unit simultaneously
following synchronization.