Planning The Quorum Disk; Installation Of The External Storage System - Hitachi G1000 User Manual

• RCU Target ports: Receive remote copy commands and data from the
Initiator ports on a connected storage system. One RCU Target port can
be connected to a maximum of 16 Initiator ports.
The number of remote paths that can be specified does not depend on the
number of ports. The number of remote paths can be specified for each
remote connection.
• Target ports: Connect the storage system to the host servers. When a
server issues a write request, the request is sent from a Target port on
the storage system to a VSP G1000 volume.
• External ports: Connect the storage system to external storage systems
configured using Universal Volume Manager. The external storage system
for the GAD quorum disk is connected to an external port on the primary
and secondary storage systems.

Planning the quorum disk

An external storage system must be prepared for the GAD quorum disk.
Review the information in the following sections when planning the quorum
disk:
• Installation of the external storage system on page 3-10
• Relationship between the quorum disk and number of remote connections
on page 3-11
• Response time from the external storage system on page 3-15

Installation of the external storage system

The external storage system can be installed in the following locations,
depending on the number of sites in your configuration:
• In a three-site configuration, the external storage system is installed in a
third site away from the primary and secondary sites. I/O from servers
continues if any failure occurs at the primary site, the secondary site, or
the site where the external storage system is installed.
3-10
Hitachi Virtual Storage Platform G1000 Global-Active Device User Guide
Planning for global-active device