474 IBM System Storage DS6000 Series: Copy Services with IBM System z
Figure 31-5 TPC for Replication - Global Mirror Copy Sets
31.5.2 TPC for Replication session
TPC for Replication uses a session concept that is similar to what Global Mirror for System z
(XRC) uses.
A session is a logical concept that gathers multiple Copy Sets, representing a group of
volumes with the requirement to provide consistent data within the scope of all involved
volumes. Commands and processes performing against a session apply these actions to all
Copy Sets within the session. Again, this is similar to a Global Mirror for System z (XRC)
session.
Figure 31-6 on page 475 shows an example of two storage servers at the local site and two
corresponding storage servers at the remote site. The example further assumes that a Metro
Mirror relation is established to replicate data between both sites.
Copy Set
Copy Set
Remote Site
Local site
Primary
Primary
A
P1
Primary
Primary
Primary
A
S2
Secondary
FlashCopy
Primary
Primary
J2
Tertiary
Primary
Primary
A
S1
Secondary
FlashCopy
Primary
Primary
J1
Tertiary
Primary
Primary
A
P2
Primary
Global Copy
Global Copy
PPRC links