There are two servers in this sample GAD+UR 3DC delta resync configuration. One server is connected to the primary storage system and the GAD secondary storage system. The other server is connected to the UR secondary storage system. The servers have the following components:
- CCI: Manages the configuration of the GAD/UR/delta UR pairs.
- Configuration definition file: Text file that contains the configuration information for the command device and the GAD/UR/delta UR pairs. It is used by CCI to manage the GAD/UR/delta UR pair configuration.
- Multi-path software: Controls the redundant paths from the host to the P-VOL or S-VOL.
- Cluster software at the primary site and
GAD secondary site*: Provides clustering of the active-active configuration between the primary host and the
GAD secondary host. In addition, the cluster software on the
UR secondary host provides clustering of the active-passive configuration in which the primary/GAD secondary hosts are active between the primary/GAD secondary hosts and the
UR secondary host.
* This item does not apply to the sample configuration described in this chapter. In the sample in this chapter the primary host and GAD secondary host are combined.
- Cluster software at the UR secondary site: Provides clustering of the active-passive configuration in which the remote host becomes the standby host between the primary/secondary host and the remote host.
- Application (Active) at the primary site and GAD secondary site: Active application. Both primary and secondary hosts are active.
- Application (Standby) at the UR secondary site: Standby application.