HP StorageWorks XP Remote Web Console Software - Manual (Page 66)

66 Continuous Access XP Journal operations requirements and restrictions
secondary data volumes in the secondary site are made in the same order that updates to Continuous
Access XP Synchronous P-VOL in the primary site are made.
As explained previously, when the host in the primary site issues an I/O request to the Continuous Access
XP Synchronous P-VOL, data is restored asynchronously to the Continuous Access XP Journal secondary
data volume in the secondary site in a remote location.
Figure 28 Basic behavior in 3DC cascading configuration
If a Continuous Access XP Synchronous pair is suspended in a 3DC cascading configuration, you can
resynchronize the pair using a differential copy. If a Continuous Access XP Journal pair is suspended, you
can resynchronize the pair using a differential copy.
NOTE: To perform disaster recovery from a failure in the primary site in a 3DC cascading configuration,
ensure that the Continuous Access XP (synchronous) P-VOL’s fence level is Data. If this fence level is
specified, you can perform disaster recovery using the Continuous Access XP Journal secondary data
volume containing data stored in the Continuous Access XP Synchronous P-VOL.
Hardware configuration
This section explains the hardware configuration for a 3DC cascading configuration using Continuous
Access XP (synchronous) and Continuous Access XP Journal. In a 3DC cascading configuration, three
arrays are required. HP recommends that you install RAID Manager XP on hosts in the primary,
intermediate, and secondary sites. For Command View XP, a management station is required for these
sites. The following explains hardware configuration for these sites.
• Local array at the primary site
• Continuous Access XP Synchronous installed
• Continuous Access XP Synchronous P-VOL
• Local array at the Intermediate site
• Continuous Access XP Synchronous installed
• Continuous Access XP Journal installed
• Volume used as a Continuous Access XP (synchronous) S-VOL and a Continuous Access XP Journal
primary data volume
• Continuous Access XP Journal master journal volume
• Local array at the remote site
• Continuous Access XP Journal installed
• Continuous Access XP Journal secondary data volume
• Continuous Access XP Journal restore journal volume
Setup procedure
This section explains the procedure for setting up a 3DC cascading configuration using Continuous
Access XP Synchronous and Continuous Access XP Journal.
1. Install Continuous Access XP Synchronous and Continuous Access XP Journal. Configure ports and
journal groups.