HP XP P9500 Storage - Manual (Page 132)

•
When the Continuous Access Synchronous Z pair is recovered, the Continuous Access Journal
Z pair in Duplex or Pending status is automatically split by the system.
•
The fence level of the Continuous Access Synchronous Z M-VOL must be Data.
•
3DC Cascade is not supported for multiple primary and secondary systems.
•
The response time for host I/Os will be the response time for Continuous Access Synchronous
Z operation plus the creation time of journal data in the intermediate site.
•
The utilization rate on the primary site with a 3DC cascading configuration is higher than if
Continuous Access Journal Z and a Continuous Access Synchronous Z systems are used
independently.
•
When the status of the Continuous Access Synchronous Z pair and the Continuous Access
Journal Z pair is Duplex and perform the copy operation to the Continuous Access Synchronous
Z pair by using Compatible FlashCopy, the status of the Continuous Access Synchronous Z
pair becomes Pending Duplex and the Continuous Access Journal Z pair will be suspended.
Procedure for setting up 3DC cascade
To set up a 3DC cascading configuration
1. Install and setup Continuous Access Synchronous Z and Continuous Access Journal Z on the
required systems.
2. Create the Continuous Access Synchronous Z pair on the primary system. See HP StorageWorks
P9000 Continuous Access Synchronous for Mainframe Systems User Guide for instructions.
3. When Continuous Access Synchronous Z pair status is Duplex, create the Continuous Access
Journal Z pair on the secondary system using the Continuous Access Synchronous Z R-VOL as
the Continuous Access Journal Z P-VOL. Mirror ID must be set between 1 and 3.
WARNING! Make sure that the Continuous Access Synchronous Z pair status changes to Duplex
before the Continuous Access Journal Z pair status changes to Duplex. If you have made a request
for changing the Continuous Access Journal Z pair status to Duplex before the Continuous Access
Synchronous Z pair status changes to Duplex, the request is rejected.
3 data center multitarget configuration
As illustrated below, the M-VOL is paired with the Continuous Access Synchronous Z secondary
volume (R-VOL) and the Continuous Access Journal Z S-VOL at separate remote sites in a 3DC
multitarget configuration. The Continuous Access Synchronous Z site is at an intermediate distance;
the Continuous Access Journal Z site is located at a greater distance.
Figure 21 3 data center multitarget (3 DC multitarget)
The host issues an update to the production volume and, synchronously, to the Continuous Access
Synchronous Z R-VOL. As with a standalone Continuous Access Journal Z system, the update data
is asynchronously written from the primary volume (P-VOL) to the Continuous Access Journal Z
S-VOL.
132 Continuous Access Journal Z configurations with Continuous Access Synchronous Z