Extended consistency groups – HP StorageWorks XP Remote Web Console Software User Manual
Page 57
Hardware Configuration (When More Than One Primary and Secondary Storage
System are Used)
This section explains hardware configuration when more than one primary and secondary subsystem
are used.
It is recommended that Business Continuity Manager is installed on the host in the primary and
secondary sites. XP Remote Web Console PCs must be installed in both of these sites. Also, disk
subsystem settings must be made so that Business Continuity Manager can be used. For detailed
information about settings required for using volumes in a remote site, see the Business Continuity
Manager user's guide.
Up to four primary subsystems and up to four secondary subsystems can be used. For example,
you can use four primary subsystems and four secondary subsystems. Also, you can use two primary
subsystems and one secondary subsystem.
The supervisor DKC and subordinate DKCs must be mutually connected in the secondary site, so
that arbitration processing can be performed. Also, remote command devices must be created in
the supervisor DKC. For details on secondary subsystems connections and remote command devices,
see
“Connections Among Secondary Storage Systems” (page 61)
and the HP StorageWorks XP
External Storage user guide for XP12000/XP10000 Disk Arrays and SVS 200.
Setup Procedure (When More Than One Primary and Secondary Subsystem are
Used)
1.
Install URz on subsystems in the primary and secondary sites.
2.
Make settings on ports and journal groups of the subsystems in the primary and secondary
sites.
3.
Create command devices in secondary subsystems.
4.
Create remote command devices in the supervisor DKC, and then map them to command
devices in the subordinate DKCs.
5.
Create URz volume pairs.
6.
With the remote command devices created in step 4, use the supervisor DKC to register journal
groups of secondary subsystems in an extended consistency group.
Extended Consistency Groups
To perform remote copy operations between more than one primary storage system and more than
one secondary storage systems while maintaining data consistency, you must register journal
groups in an extended consistency group (abbreviated as EXCTG). An extended consistency group
is a collection of journal groups. This manual uses the term "primary EXCTG" to see an extended
consistency group for primary storage systems. This manual also uses the term "secondary EXCTG"
to see an extended consistency group for secondary storage systems.
To perform remote copy operations between more than one primary storage system and more than
one secondary storage systems while maintaining data consistency, you must configure a secondary
EXCTG. Also, it is recommended that you configure a primary EXCTG, because the primary EXCTG
will be necessary if you need to reverse the primary and secondary sites after a failure occurs.
You can register up to four journal groups in an EXCTG (when using XP Remote Web Console) or
six (when using Business Continuity Manager). You can configure different storage systems in the
same extended consistency group, but you cannot register one journal group in different extended
consistency groups.
explains specifications of extended consistency groups:
Using More Than One Primary and Secondary Storage System for Remote Console
57