HP XP Racks - Manual (Page 53)

The 2DC configuration
A 2DC configuration is used to perform a copy operation from the primary site to the secondary
site.
Figure 12 (page 53) gives an example of a 2DC configuration.
Figure 12 2DC configuration example
A 2DC configuration offers the following advantages:
•
If a disaster occurs at the primary site, the S-VOL of the TrueCopy Asynchronous for Mainframe
or Continuous Access Journal Z copy pair at the secondary site can be used to restart and
continue operations without waiting for primary site recovery.
•
When a disaster occurs at the primary site, even if the S-VOL for the TrueCopy Asynchronous
for Mainframe or Continuous Access Journal Z copy pair on the secondary site cannot be
used for a recovery, the operation data is not completely lost because there is also a backup
on the Business Copy Z copy pair S-VOL.
•
Operation data can be backed up to a Business Copy Z copy pair S-VOL, minimizing the
time necessary to recover the backup data.
The 3DC configuration
A 3DC configuration consists of a primary site and two other sites, and is used to perform remote
copies from the primary site. By allocating copies to three different sites, the 3DC configuration
minimizes the changeces of losing data in the event of a disaster.
Continuous Access Synchronous Z is used to perform operations for nearby sites, and Continuous
Access Journal Z is used to perform operations for distant sites. Make sure that the copy pairs
between each site are always in the DUPLEX status.
A 3DC configuration offers the following advantages:
•
The copy pairs between each site can always be left in the DUPLEX status to set the retention
time for the update order consistency to 0.
•
The copying operation is simple.
Because the copy pairs between sites can be set to maintain DUPLEX status, once a copy pair
has been changed to DUPLEX status it is no longer necessary to specify operation on that
copy pair unless the status is suspended by an error or the site is damaged by a disaster.
Replication products and data center configurations 53