IBM DS6000 - Manual (Page 241)

Chapter 18. Global Copy options and configuration 217
18.9 Other planning considerations
Figure 18-6 illustrates the use of Global Copy for point-in-time backup solutions.
Figure 18-6 Global Copy environment
When you are planning to use Global Copy for point-in-time backup solutions, and if you are
going to have tertiary copies, then within the target disk subsystem you should have an
available set of volumes ready to become the FlashCopy target.
If your next step is to move the tertiary volumes onto tapes, then you must ensure that the
tape resources are capable of handling these dump operations in between the point-in-time
checkpoints, unless you have additional sets of volumes ready to become alternate
FlashCopy targets.
channel
extender
channel
extender
Flas
hC
opy
secondary
tertiary
primary
Global Copy
consistent tertiary
copy of data
Secondary Site
Primary Site
minimum performance impact
fuzzy copy of data